MS001 How the structural biologists and the PDB drive innovation in fundamental biology, biomedicine, biotechnology, and the energy sciences

Co-Chairs: Genji Kurisu & Jasmine Young

Invited Speakers: Jennifer Fleming, Janet Iwasa & Daisuke Kihara

SPONSORING COMMISSION: Biological Macromolecules

This session will explore how structural data from the PDB accelerates the development of novel therapeutics, enables structure-based drug design, and informs our understanding of disease mechanisms. Speakers will highlight recent breakthroughs, emerging computational tools, and the growing role of AI in leveraging PDB data for precision medicine. By bridging molecular structures with clinical applications, this session will showcase the PDB’s critical role in shaping the future of healthcare.

MS002 Quasicrystalline, incommensurately modulated, and composite phases: structural complexity and emerging properties

Co-Chairs: Julia Dshemuchadse & Thomas Doert

SPONSORING COMMISSION: Aperiodic Crystals

CO-SPONSORING COMMISSION: Magnetic Structures

SUPPORTING COMMISSION: NMR Crystallography and Related Methods

Quasicrystalline, incommensurately modulated, and composite phases represent a class of materials characterized by the absence of conventional translational symmetry despite exhibiting crystalline order. The interplay between their structures and the corresponding physical properties remains an area of active research. This microsymposium will bring together experts using theoretical, experimental, and computational approaches to discuss recent advances in understanding aperiodic structures, both magnetic and non-magnetic, and the origin of their order.

MS003 Self-assembly and structure of the world around us: food, detergents, and paints

Co-Chairs: Tom Fitzgibbons & Susana Teixeira

SPONSORING COMMISSION: Small Angle Scattering

The things we use and consume in everyday life often have unique and complex structures that give rise to their physical properties and dictate their overall performance. Small-angle X-ray and neutron scattering play a key role in gaining insight into these structures. This microsymposium will explore the role of formulation design and process engineering in the self-assembly of materials and their use in applications ranging from food to soaps and cosmetics to paints. A mixture of academic and industrial researchers will describe how advances in measurement science using small-angle scattering enable the next generation of high-performance, healthier, and more sustainable products.

MS004 Crystal growth, phase transitions, and applications of multi-ferroic, multi-functional, and other complex materials

Co-Chairs: Weiwei Xie & Davide Delmonte

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Crystal Growth and Characterization of Materials

SUPPORTING COMMISSION: Powder Diffraction

This microsymposium will explore recent synthetic, experimental, theoretical, and computational work that illuminates structure-property relationships in functional and multifunctional materials. “Functional” implies a material’s capacity to respond to stimuli, and “multifunctional” implies different and sometimes complementary physical properties that coexist in a unique crystallographic phase. Such material properties can enable the realization of new devices with improved characteristics such as sustainability, miniaturization, self-healing, adaptation, and self-assembly. Material classes and applications of particular interest include ferroics and piezoelectrics, multiferroics, photoferroelectrics, magneto-, electro-, and barocalorics, coupled sensing-actuating phases, and soft bio-inspired or hybrid materials grown in powder, single-crystal, film, or nanostructural form. Functional behaviors involving antiferromagnetic order are also of interest.

MS005 Diffraction microstructure imaging for ceramics

Co-Chairs: Darren Pagan & Amanda Krause

SPONSORING COMMISSION: Diffraction Microstructure Imaging

Many mesoscale diffraction microstructure imaging (DMI) techniques were originally developed to study the evolution of metallic alloys during thermomechanical processing. As these techniques mature, their application to other material systems, including ceramics, is rapidly expanding. Ceramics present challenges not typically encountered in metallic alloys, such as lower-symmetry crystal structures, the prevalence of crystallographically related domains, and usage in electromagnetic fields. This microsymposium will highlight recent research on the use of DMI techniques for ceramic materials, including novel DMI reconstruction methods, in operando measurements, and DMI during ceramic processing.

MS006 Crystal structure prediction: impact, advancements, and future directions

Co-Chairs: Susan Reutzel-Edens & Jonas Nyman

SPONSORING COMMISSION: Structural Chemistry

CO-SPONSORING COMMISSION: CommDat

It has been 37 years since John Maddox famously stated that our inability to predict the crystal structures of compounds was one of the “continuing scandals” in the physical sciences. Since then, enormous progress has been made, to the point that computational crystal structure prediction (CSP) has become widespread in both industrial and academic settings, being used to understand structure-property relationships and to inform decision-making on a daily basis. Despite this progress, CSP remains an evolving field as new targets with more challenging chemistries are pursued and state-of-the-art computational techniques are implemented. This microsymposium will showcase two broad aspects of CSP technology: first, the practical impact of CSP in predicting the packing of compounds and their associated properties, and second, the methodological advancements that have expanded its utilization. Contributions from both organic and inorganic CSP studies will demonstrate the broad impact, advances, and future directions of crystal structure prediction methodology, which has all but removed the stigma of having once been dubbed a “continuing scandal.”

MS007 Advancing subperiodic structure descriptions: rods, lines, layers, and faulting

Co-Chairs: Berthold Stoeger & Peter Khalifah

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: Mathematical and Theoretical Crystallography

This microsymposium addresses the crystallography of structures that are periodic in fewer than three dimensions. Complex crystallographic features such as twinning, stacking faults, or polytypism often arise when structures have subperiodic components (layers with 2D periodicity or rods with 1D periodicity). The crystallographic layer (80 types) and rod groups (75 types) play a central role in describing these phenomena, as do the noncrystallographic groups used to characterize the symmetry of nanotubes. The theory of subperiodic groups provides a key framework for understanding growth mechanisms and surface structures of crystals, relevant for applications such as chemical vapor deposition, epitaxial film growth, and faulting in layered battery cathode materials. While mature software tools exist for symmetry analysis of 3D periodic structures (e.g., MISSYM, ADDSYM, and PSEUDO), analogous tools for analyzing structures with lower-dimensional periodicity are lacking. This microsymposium will provide an opportunity to present fundamental algorithms and approximations for characterizing symmetry, to discuss software tools for suggesting, implementing, and validating symmetry assignments, and to describe the analysis of experimental data for real materials, while also highlighting unresolved challenges in the field.

MS008 The impact of IUCr Commissions on global science

Co-Chairs: Ella Schmidt & Thomas Proffen

SPONSORING COMMISSION: IUCr Early Career Scientist Division

CO-SPONSORING COMMISSION: Committee for the Maintenance of the CIF Standard (COMCIFS)

Did you know the International Union of Crystallography (IUCr) has 22 Commissions covering all branches of structural science, crystallographic techniques, and computing? Commission members are a diverse group of experts whose work ranges from driving and communicating scientific advances relevant to the IUCr, to implementing standards for data processing and scientific communication, as well as organizing and promoting conferences, specialized schools, and workshops. Another important role of the Commissions is to promote the IUCr journals, ensuring the long-term future of the Union. The aim of this microsymposium is for participants to get to know the Commissions better and learn about their work, with examples of their initiatives. More importantly, the microsymposium will also provide a forum for input from the community on the future work of the Commissions and promote channels for collaboration with the new Early Career Scientists Division (ECSD) to ensure generational renewal and diversity among Commission members.

MS009 Advances and applications in 4D-STEM

Co-Chairs: Andrew Stewart & Laure Bourgeois

Invited Speakers: Arthur Blackburn, Christoph Koch & Muriel Veron

SPONSORING COMMISSION: Electron Crystallography

Four-dimensional scanning transmission electron microscopy (4D-STEM) is a powerful approach that uses electron diffraction and imaging with small scanning electron probes to determine structural information at the atomic scale. The large amount of information obtained during a 4D-STEM experiment enables a wide range of applications in the high-resolution study of materials. This microsymposium will focus on the continued advancement of 4D-STEM methods as well as the many new and exciting structural studies made possible by this technique.

MS010 High-Pressure and High-Energy Density Science: Synthesis, In-Situ characterization, and Beyond

Co-Chairs: Zhidan Zeng & Masaaki Matsuda

SPONSORING COMMISSION: High Pressure

CO-SPONSORING COMMISSION: Magnetic Structures

SUPPORTING COMMISSION: Synchrotron and XFEL Radiation

This micro-symposium highlights the transformative role of pressure in tailoring the properties of novel materials, from discovery to application. High-pressure and high-energy density (HED) science explores the fundamental behavior of matter under extreme conditions, providing critical insights into phase stability (e.g. in planetary interiors), material synthesis, and the exotic physics of electronic and magnetic materials, which are otherwise inaccessible under ambient conditions. With the rapid advancements in X-ray free-electron lasers (XFELs), synchrotrons, neutron scattering sources, and dynamic compression techniques, researchers can now probe matter at unprecedented pressures, temperatures, and time scales. Advances in in-situ characterization techniques now allow researchers to observe real-time changes on atomic and electronic level under pressure, revealing how pressure-driven transformations lead to new optical, magnetic, and electrical properties. Join leading researchers as they discuss groundbreaking discoveries, cutting-edge methodologies, and the future of high-pressure materials science.

MS011 Synergies between cryoEM, diffraction methods, and complementary biophysical measurements

Co-Chairs: Holger Stark & TBD

SPONSORING COMMISSION: Biological Macromolecules

CO-SPONSORING COMMISSION: Synchrotron and XFEL Radiation

X-ray and electron-based structural biology are at the forefront of elucidating macromolecular structures, pushing the boundaries of resolution and experimental capabilities. With the rapid development of cryo-EM, microcrystallography, and serial femtosecond crystallography, researchers now have an expanding toolkit to explore biological structures under increasingly native conditions. This session will focus on the latest advancements in X-ray and electron structural biology, including new detector technologies, phase retrieval methods, hybrid approaches combining crystallography and cryo-EM, and applications in challenging biological systems. Despite these advances, critical challenges remain. The need for high-quality sample preparation, data collection strategies, and improved integration of complementary methods continues to drive innovation. We will explore cutting-edge developments in synchrotron- and XFEL-based macromolecular crystallography, cryo-EM, and cryo-ET, as well as computational methods that enhance structure determination across these modalities.

MS012 Next-generation validation metrics for macromolecular structures

Co-Chairs: Dominika Borek & Deborah Harrus

SPONSORING COMMISSION: Biological Macromolecules

This microsymposium will explore validation strategies and metrics, including machine learning-assisted assessment, atomic-level precision metrics, and cross-validation with experimental data and computational techniques. Speakers may discuss new developments in error detection, bias correction, ensemble model validation, and quality assessment pipelines, such as those used in databases like the PDB and CCDC. This microsymposium will provide insights into the future of validation for structural models across crystallography, cryo-EM, and integrative modeling.

MS013 Big data and crystallography

Co-Chairs: Olga Anosova & Santosh Panjikar

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: Mathematical and Theoretical Crystallography

The rapid growth of crystallographic data presents both challenges and opportunities for structural science. Harnessing big data techniques has become crucial for mining and analyzing massive crystal databases, enabling the discovery of trends and patterns that can advance our understanding of molecular structures and interactions. Computational approaches such as machine learning, artificial intelligence, and data-driven analytics are revolutionizing how crystallographic data is processed, allowing researchers to identify hidden correlations, optimize experimental conditions, and refine structural models with unprecedented accuracy. The integration of diverse datasets from different experimental techniques further enhances the power of big data in crystallography, facilitating comprehensive insights into structural dynamics and function. This microsymposium will explore the latest advancements in big data applications within crystallography, addressing challenges related to data management, scalability, and standardization.

MS014 Magnetism for emerging technologies

Co-Chairs: Stuart Calder & Yusuke Kousaka

SPONSORING COMMISSION: Magnetic Structures

For advancing next-generation technologies, from energy-efficient information storage and multifunctional materials to efficient energy conversion, magnetism is one of the key properties. This microsymposium will explore cutting-edge research at the intersection of fundamental mechanisms and novel applications, with a focus on the relationship between magnetic structure and properties. Key topics include spintronic materials in the context of low-power electronics and coupling phenomena such as magnetoelasticity and multiferroicity. Advances in magnetocaloric and spin-thermoelectric materials will also be in scope, highlighting their potential for energy conversion applications. By sharing the latest fundamental insights, this microsymposium aims to stimulate interdisciplinary discussions and facilitate research activity in the field of applied magnetism.

MS015 Engaging all in crystallography

Co-Chairs: Alexis Nelson & Helen Maynard Casely

SPONSORING COMMISSION: Crystallographic Teaching

This microsymposium will focus on how to effectively engage students at any level, as well as the wider public, with crystallography. Specific topics may include training and mentoring in research that involves crystallography, pedagogy and the development of crystallography teaching infrastructure, the presentation and evaluation of outreach efforts, effective involvement of students at synchrotron facilities, and the maintenance of crystallography resources for engaging students.

MS016 Coordination chemistry: ligand design, crystallographic studies, and applications in medicinal inorganic chemistry

Co-Chairs: Natalia Alvarez & Alice Brink

SPONSORING COMMISSION: Structural Chemistry

This microsymposium will explore coordination chemistry and focus on the rational design of ligands, crystallographic studies of metal complexes, and their applications in medicinal inorganic chemistry. The session will address advanced strategies for developing customized ligands capable of modulating the electronic, geometric, and reactive properties of metal complexes. The latest trends in the synthesis and characterization of these systems will be discussed, with an emphasis on the use of single-crystal X-ray diffraction techniques to elucidate their structures at the atomic level. In the context of medicinal inorganic chemistry, the microsymposium will highlight the therapeutic potential of metal complexes such as those of copper(II), platinum(II), or technetium-99m—metallic ions that have played a significant role in metalloprotein interactions and modern drug development. Research highlighting structural aspects of mechanism of action, chemical reaction mechanisms, and structure-activity relationships, including the generation of reactive oxygen species (ROS) and interactions with target biomolecules, is welcomed. The integration of crystallographic studies with biological assays will be emphasized as an essential tool for the development of new therapeutic agents and controlled drug delivery systems. Key topics will include the design of ligands to achieve specific functionalities in metal complexes, the facilitation of ligand-biomolecule binding, post-synthetic modification strategies, and the description of crystal intermolecular interactions and their relationship with the physicochemical properties of the complexes. This multidisciplinary approach aims to unite fundamental advances in coordination chemistry with innovative applications in medicine, promoting the creation of functional systems to address global health challenges.

MS017 Quantum crystallography computing applications in electron density and chemical bonding

Co-Chairs: Florian Kleemiss & Christian Jelsch

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: Quantum Crystallography

SUPPORTING COMMISSION: COMCIFS

Quantum crystallography computing has emerged as a powerful approach to enhance electron density interpretation and gain deeper insights into chemical bonding within complex crystalline systems. By integrating quantum mechanical calculations with experimental crystallographic data, researchers can achieve a more accurate representation of electron distributions, particularly in systems containing metal centers and intricate bonding environments. This approach complements traditional methods by enabling the refinement of atomic models and the identification of subtle electronic effects such as charge delocalization, polarization, and hybridization. The application of quantum crystallography spans diverse fields, including materials science, structural biology, and pharmaceutical research, where it provides significant potential for advancing the understanding of metalloproteins, coordination complexes, and catalytic systems. Advances in computational methodologies such as density functional theory (DFT) and wavefunction-based approaches are continuously improving the accuracy and efficiency of these calculations, bridging the gap between theoretical predictions and experimental observations. This microsymposium aims to explore recent developments in quantum crystallography computing, focusing on innovative computational approaches for electron density and chemical bonding analysis, challenges in integrating quantum and experimental data, applications in structural biology, materials science, and catalysis, as well as emerging trends and future directions in quantum crystallographic computing. The microsymposium will provide a platform for researchers to discuss current applications, challenges, and advancements in the field, fostering collaboration and innovation in experimental and computational quantum crystallography.

MS018 New sources - advancing next-generation photon and neutron science

Co-Chairs: Helmut Schober & Harry Westfahl, Jr.

SPONSORING COMMISSION: Synchrotron and XFEL Radiation

The development of next-generation X-ray and neutron sources is revolutionizing experimental science, enabling unprecedented capabilities in imaging, spectroscopy, and structural determination across multiple disciplines. With the advent of diffraction-limited storage rings (DLSRs), high-repetition-rate X-ray free-electron lasers (XFELs), and advanced neutron sources, researchers can now probe materials and biological systems with greater sensitivity, resolution, and temporal precision. This microsymposium will highlight the latest advancements in synchrotron radiation, free-electron lasers, neutron sources, and high-brightness beamlines, as well as their applications in physics, chemistry, biology, and materials science.

MS019 Modular structure of inorganic and mineral compounds

Co-Chairs: Berthold Stöger & Isabella Pignatelli

SPONSORING COMMISSION: Inorganic and Mineral Structures

CO-SPONSORING COMMISSION: Aperiodic Crystals

Modular structures are built of distinct layers, rods, or blocks that can be arranged in different ways. They are ubiquitously found in synthetic inorganic chemistry as well as in mineral compounds and lead to challenging crystallographic problems such as OD structures, polytypes, twinning, allotwinning, or diffuse scattering owing to disorder. Moreover, recognition of the modular character of a structure allows for classification into structure families. The symmetry description of modular structures, as well as their modeling using approaches such as superspace formalism, is an active area of research.

MS020 Metastabilities of materials under dynamic compression

Co-Chairs: Amy Lazicki & Sakura Pascarelli

SPONSORING COMMISSION: High Pressure

This microsymposium will focus on the behavior of metastable materials under dynamic compression, an important area of research with implications for physics, planetary science, and the study of exoplanets. Dynamic compression experiments, often achieved through high-energy lasers or shock waves, reveal how materials transition into metastable states that defy equilibrium predictions. These metastable phases can exhibit unique properties, offering insights into material strength, phase transformations, and energy storage mechanisms. Understanding these phenomena is not only fundamental to advancing materials science but also essential for modeling the interiors of exoplanets, where extreme pressures and temperatures create similar conditions. This microsymposium will bring together researchers to discuss advanced experimental techniques and innovative approaches that shed light on the metastable behavior of materials under dynamic compression.

MS021 21st Century Structural Enzymology

Co-Chairs: Ashwin Chari & Janet Smith

SPONSORING COMMISSION: Biological Macromolecules

CryoEM has yet to reach its full potential as predicted by theoretical considerations. Detectors and other components of the instruments can still be improved to enable the full potential of the technique. This microsymposium will gather leaders in the field who are working to build instruments capable of higher resolution, higher throughput, and broader accessibility. Topics may include stages, continuous tilting, detectors for fast tomography, laser phase plates, fast objective lens current modulation, FIB milling, pulsed laser devitrification, affordable low-voltage cryoEM, cryo holography, 4D STEM, and ptychography.

MS022 Structural insight into mechanisms of disease in humans, animals, and plants

Co-Chairs: Hong Zhou & Fasseli Coulibaly

SPONSORING COMMISSION: Biological Macromolecules

Understanding disease mechanisms at a structural level is crucial for developing targeted therapies. Structural insights involve understanding how molecular structures, especially proteins, nucleic acids, and small molecules, contribute to the development and progression of diseases. This microsymposium will include topics such as protein misfolding and aggregation, mutations and structural defects, cancer-related structural changes, and virology.

MS023 Spin groups and magnetic symmetry (theory and applications)

Co-Chairs: Oksana Zaharko & Qihang Lu

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: COMCIFS

SUPPORTING COMMISSION: Crystallographic Nomenclature and the International Tables

Magnetic symmetry analysis is an essential tool for characterizing magnetic materials. This microsymposium will focus on the theory and applications of magnetic symmetry, with particular emphasis on spin groups in both space and point groups. These groups have recently reemerged as fundamental tools for crystallographic characterization of magnetic structures. They are also used to resolve phenomena in magnetic materials independent of the coupling of spin and lattice degrees of freedom, such as in the case of altermagnetism. Invited talks will present recent advances in the theory and applications of spin groups, and contributions on any studies where magnetic symmetry plays a fundamental role are also welcome.

MS024 Accelerating crystallography: high-throughput methods and automation

Co-Chairs: Uwe Müller & Daren Fearon

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: Biological Macromolecules

SUPPORTING COMMISSION: Synchrotron and XFEL Radiation

The automation of structure determination pipelines has revolutionized crystallography by streamlining the process from data collection to refinement. Advances in computing and artificial intelligence have enabled the development of sophisticated algorithms that automate critical tasks such as data processing, phasing, model building, and refinement, significantly reducing human intervention and improving throughput. These automated pipelines provide real-time feedback during data collection, allowing researchers to make informed decisions, optimize experimental parameters, and ensure high-quality data acquisition. Case studies demonstrate the effectiveness of these systems in various experimental settings, highlighting improvements in data accuracy, reproducibility, and efficiency. The integration of machine learning and cloud-based solutions further enhances the adaptability and scalability of these pipelines, making them accessible to a wider research community. This microsymposium will discuss the latest innovations in automated structure determination, fragment screening, the challenges associated with automation, and future prospects for fully autonomous crystallographic workflows.

MS025 Methods for structure determination of complex systems using NMR crystallography/computational approaches

Co-Chairs: Brijith Thomas & Rachel W. Martin

SPONSORING COMMISSION: NMR Crystallography and Related Methods

CO-SPONSORING COMMISSION: Structural Chemistry

SUPPORTING COMMISSION: Quantum Crystallography

There have been considerable advances in using NMR parameters for the development of novel structural tools for advanced materials. Machine learning approaches (for example, SHIFT-ML), novel crystal-structure prediction tools (QNMRX-CSP, NMR-CSP combined methods for highly flexible molecules), DFT-based approaches, and combined MD/NMR methods have been used extensively to provide unique insights into the structure and dynamics of different classes of materials, from molecular pharmaceutical solids to open-framework materials, functional oxides, and energy materials. This microsymposium will focus on highlighting these advances with the aim of making them better known to non-NMR audiences in academia and industry. In addition, there is considerable interest in the characterization of amorphous solids and other complex materials for which diffraction-based methods struggle to deliver vital atomic-level information.

MS026 Coherent scattering and X-ray photo correlation spectorscopy enabled by new sources and instrumentation

Co-Chairs: Aline Ribeiro Passos & Eric Dufresne

SPONSORING COMMISSION: Small Angle Scattering

This microsymposium will highlight cutting-edge research in coherent-based techniques such as XPCS and phase-contrast imaging methods, including CDI, ptychography, holography, and BraggCDI, with applications across biology, materials science, and physics. Discussions will also cover technical developments such as operando studies, sample environments, fast detectors, and advanced algorithms needed to leverage the unique capabilities of diffraction-limited storage rings. By addressing emerging challenges and fostering collaboration, this microsymposium aims to drive progress in the field of coherent and phase-contrast imaging.

MS027 Coordinated efforts towards open data for global open science

Co-Chairs: John Helliwell & Bridget Murphy

Invited Speakers: Andy Gotz, Genji Kurisu & Kruna Vukmirovic

SPONSORING COMMISSION: CommDat

Open science is a force for good and an enabler of research, irrespective of economics or politics. It is by definition a global endeavor and is driven by open data. For open science to thrive, open data needs to be produced, managed, and made available in a coordinated manner. However, this coordination requires funding and political will, and fortunately, these are now beginning to come to pass. Large-scale initiatives are now producing systems to facilitate and coordinate open data, typically funded by national or regional organizations. There is some general coordination of these initiatives through global organizations such as CODATA; however, it is also imperative to coordinate at a disciplinary level, and this microsymposium is intended to foster these connections. This is a general topic applicable to all commissions generating open data. In practice, the open science movement follows the guideline “as open as possible, as closed as necessary” to protect, for example, endangered species and their locations, and it is feasible to envisage other such situations. Intellectual property rights can also apply, for instance, in the case of patents and industry.

MS028 Particle engineering: from interactions to morphology

Co-Chairs: Elena Simone & Marijana Dakovic

SPONSORING COMMISSION: Structural Chemistry

The design of crystalline particles is challenging in many fields such as pharmaceuticals, agrochemicals, pigments, since properties like flowability, tabletability, wettability, and solubility are crucial for the development of solid materials. Proper engineering of crystalline particles through crystallization is essential to address manufacturing issues. Understanding the inter-relationships among structure, property, performance and processing can guide research and provide engineering solutions. This symposium highlights the role of structural chemistry, crystallography and crystal engineering in providing tools to understand particle behaviour at the scale of interactions, morphology, surface characteristic and how these translate in particle properties.

MS029 New trends in hybrid pixel photon counting detectors

Co-Chairs: Arthur H Liu & Jean Marie Polli

SPONSORING COMMISSION: High Pressure

CO-SPONSORING COMMISSION: Crystallography of Materials

Advanced large-area hybrid pixel photon-counting detectors enable high signal-to-noise ratio, high speed, and efficiency in photon detection for various synchrotron and laboratory applications. This provides opportunities to advance photon science, including X-ray diffraction and crystallography, scattering, spectroscopy, and imaging. This microsymposium will highlight efforts aimed at extending the photon detection range from lower energies through active sensors and to higher energies with high-Z materials, with special focus on potential improvements for synchrotron and other lab-based demands. New methods to reduce effective pixel size, minimize stacking, and improve energy resolution through intelligent pixel processing will be discussed. Other emerging development trends include increasing frame rates through higher-bandwidth readouts, improving hybridization processes to reduce gaps, and employing high-throughput, low-delay embedded AI and machine learning to improve real-time frame quality. Recent progress in real use cases will be emphasized

MS030 Implementing free multimedia and interactive tools to improve the teaching of crystallography

Co-Chairs: Leopoldo Suescun & Daniel Widdowson

SPONSORING COMMISSION: Mathematical and Theoretical Crystallography

CO-SPONSORING COMMISSION: Magnetic Structures

The integration of multimedia, online resources, and interactive tools in classrooms provides students with the flexibility to access materials at their own pace and convenience, thereby enhancing their learning experience. In crystallography, a wide variety of free resources such as websites, interactive applets, databases, and programs, can be implemented in courses, ranging from symmetry visualization tools to advanced programs for determining crystal structures. Many of these resources are also used by scientists in their research, offering students valuable insights into the tools and technologies commonly employed in the field. This microsymposium will explore how these tools can be applied to teaching crystallography across different academic levels and curricula.

MS031 Innovations in algorithms and computational methods in cryoEM

Co-Chairs: Alexis Rohou & Carlos Oscar Sorzano

SPONSORING COMMISSION: Biological Macromolecules

Many challenges remain in the quest to fully unlock the potential of cryoEM for structural studies of biology. How can we resolve fine details of dynamic, flexible assemblies? What is the best way to study the structures of macromolecules in their native cellular context? How can we control instruments more efficiently for high-throughput, automated high-resolution imaging? What are the optimal methods for obtaining and validating accurate and reliable atomic models for molecules of interest? For these and other challenges, the development of improved computational methods and algorithms remains a cornerstone of the field. This microsymposium will cover some of the latest computational work in cryoEM and cryoET.

MS032 Session to honor the contributions of Sine Larsen and Michael James

Co-Chairs: Gerald Audette & Leila Lo Leggio

SPONSORING COMMISSION: Biological Macromolecules

This microsymposium will honor Sine Larsen and Michael James, who made pioneering and important contributions to macromolecular crystallography and the structural characterization of enzymes. Apart from being an active scientist, Sine Larsen also gave much of her time to science organization, serving as secretary and later as president of the IUCr. Michael James was the father of macromolecular structural biology in Canada and mentor to dozens of Canadian and international researchers, spending his entire independent career in Edmonton. Given their contributions to the IUCr and to macromolecular structural biology in Canada, it is particularly fitting to honor these scientists at IUCr2026 in Calgary. Talks will focus on many aspects of enzymes, especially structural studies that yield novel insights into mechanisms and protein chemistry.

MS033 Understanding material design - eutectics, peritectics, crystal growth

Co-Chairs: Rosalba Fittipaldi & Ashwin Shahani

SPONSORING COMMISSION: Crystal Growth and Characterization of Materials

SUPPORTING COMMISSION: Crystallography of Materials

This microsymposium will highlight advances in the synthesis and crystal growth of metastable materials, eutectics, and peritectics. Understanding nucleation and growth under out-of-equilibrium conditions is crucial for controlling phase formation and stability. Emerging synthesis methods raise several important topics, including the physics of nonequilibrium pattern formation, multistep phase transformation pathways, dopant and impurity segregation at interfaces, microstructural hierarchy, metastable co-crystalline structures, and multifunctional properties. Contributions that explore novel synthetic strategies, real-time monitoring methods, and mechanistic insights into metastable crystal growth are encouraged.

MS034 Statistical and computational analysis in crystallography and spectroscopy

Co-Chairs: Reinhard Neder & Christopher Chantler

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: XAFS

SUPPORTING COMMISSION: Powder Diffraction

Material three-dimensional structures are complex, with both statistical and systematic issues in the data collected. Protein and small-molecule XRD contain large extended 3D datasets for the determination of space group, bonding, primary, secondary, tertiary, and sometimes quaternary structure, electron density, and increasingly local order and disorder. High-accuracy XAS spectra are primarily two-dimensional but incorporate additional dimensions to remove systematics and establish statistical value, aiming to determine three-dimensional structure with local but not necessarily extended order. RIXS and HERFD techniques are often intrinsically high-resolution three-dimensional datasets but can be expanded to reveal more local bonding and electronic structure. In all cases, advanced techniques to reveal and define structure are important current developments. Computational crystallography leverages advanced algorithms and data-fusion techniques to combine crystallographic data such as X-ray, electron, and neutron diffraction with complementary methodologies including spectroscopy, tomography, and scattering experiments. The integration of diverse datasets presents challenges such as data alignment, resolution discrepancies, and varying experimental conditions, necessitating the development of robust computational workflows.

MS035 New developments in in-situ and in-operando experimentation: Pushing the boundaries of diffraction experiments

Co-Chairs: Andrey Yakovenko & Julia Payne

SPONSORING COMMISSION: Powder Diffraction

CO-SPONSORING COMMISSION: Neutron Scattering

Materials research has progressed from simply characterizing structures to probing crystallographic changes as materials function within devices. To enable this, researchers are developing new sample environments that reproduce real-world operating conditions during diffraction and total scattering experiments. These advances have become vital tools for pushing the boundaries of experimentation and deepening our understanding of functional materials in action. Cutting-edge in situ and operando experiments now allow us to probe not only structural changes and mechanisms, but also the performance of complete devices under realistic conditions. This microsymposium will highlight developments in in situ and operando methodologies, including new experimental environments, their application to diverse functional materials, and approaches for exploring multiple external stimuli to achieve a holistic understanding of materials and devices under operation.

MS036 Technique development in quantum crystallography

Co-Chairs: Dylan Jayatilaka & Anna Hoser

SPONSORING COMMISSION: Quantum Crystallography

CO-SPONSORING COMMISSION: Crystallographic Computing

SUPPORTING COMMISSION: Committee for the Maintenance of the CIF Standard (COMCIFS)

A major strength of quantum crystallography is the development of computer-based methods that span modeling, refinement based on experimental data, databasing, and AI/ML applications. Quantum crystallography lies at the intersection of quantum theory and experiments aimed at measuring quantum mechanical observables within crystallography. Technique developments in the computational, theoretical, and experimental realms are sought as contributions to this microsymposium. Furthermore, with the increasing amount of information generated by quantum crystallographic techniques, the evolution of CIF dictionaries and libraries is an additional focus.

MS037 Expanding the possibilities of pharmaceutical innovation through small-angle scattering

Co-Chairs: Melissa Ann Gräwert & Kushol Gupta

SPONSORING COMMISSION: Small Angle Scattering

Recent advancements in small-angle scattering (SAS) are elevating pharmaceutical research, offering powerful tools to tackle emerging challenges in drug discovery and development. SAS provides critical insights into internal structure, stability, flexibility, and interactions under near-physiological conditions. This microsymposium will explore the latest developments in SAS techniques, focusing on their application in accelerating pharmaceutical innovation and addressing key questions in drug discovery, formulation, and delivery. Insights will include high-throughput screening of drug candidates as well as new approaches that couple online purification systems, such as asymmetrical flow field-flow fractionation (AF4), for the detailed characterization of complex and novel drug delivery systems including lipid nanoparticles (LNPs). In addition to these hardware solutions, advances in rapid acquisition of high-quality data, coupled with robust and comprehensive analysis, are enabling faster decision-making across the entire drug development process.

MS038 Aperiodic magnetic structures

Co-Chairs: Alexandra Gibbs & Oscar Fabelo

SPONSORING COMMISSION: Magnetic Structures

Aperiodic magnetic structures pose both challenges and opportunities in the study of condensed matter physics. Neutron scattering has traditionally been a key technique for investigating these systems, offering valuable insights into the connections between aperiodicity, magnetism, and material properties. More recently, advances in synchrotron radiation sources have positioned X-ray scattering as an effective alternative or complementary method for studying aperiodic magnetic structures. This microsymposium will focus on recent progress in the study of aperiodic structures, including purely magnetic aperiodic systems and those combining nuclear and magnetic aperiodicity. Contributions are especially encouraged that highlight advancements in scattering techniques, including innovations in instrumentation, improvements in data processing and analysis software, and applications to understanding aperiodic magnetic systems.

MS039 Sustainable materials for the future: synthesis, characterization, and applications

Co-Chairs: Cora Lind-Kovacs & Karena Chapman

SPONSORING COMMISSION: Crystallography of Materials

CO-SPONSORING COMMISSION: Powder Diffraction

SUPPORTING COMMISSION: Crystal Growth and Characterization of Materials

This microsymposium will highlight advances in sustainable materials for energy storage, conversion, and environmental remediation, with a focus on the insights that crystallography can bring to the rational design of sustainable materials. Ideally, this knowledge will lead to the targeted design and accelerated development of sustainable materials. Topics include batteries, nuclear materials, metal-organic frameworks (MOFs), catalysis, solar energy, hydrogen storage and separation, fuel cells, and byproduct remediation. Emphasis will be placed on the role of advanced structural techniques, including powder diffraction and pair distribution function (PDF) analysis, in understanding and optimizing material performance. Contributions that explore novel materials, characterization methods, and structure-property relationships are encouraged.

MS040 Advanced data analysis and refinement for electron diffraction data

Co-Chairs: Mauro Gemmi & Tatiana Gorelik

SPONSORING COMMISSION: Electron Crystallography

Single-crystal electron diffraction is reaching an accuracy level that approaches that of X-ray crystallography. With advancements in data collection and processing, such as the application of dynamical refinement, it is now possible to refine hydrogen positions in both organic and inorganic structures, determine partial occupancies, observe guest molecules, and establish the absolute configuration of chiral compounds. However, further improvements are needed to close the accuracy gap between electron and X-ray crystallography. This microsymposium will highlight recent developments in data collection, analysis, and modeling, as well as structure refinement techniques in electron diffraction.

MS041 Current Trends in Structure-Guided Drug Discovery I

Co-Chairs: Albert Berghuis & Anne Jecrois

SPONSORING COMMISSION: Biological Macromolecules

Unravelling structural mechanisms of drug action and positing rational drug design has been at the forefront of drug discovery and development over the past few decades, owing particularly to crystallography and NMR techniques. Modern high-resolution structural biology techniques like cryo-EM, cryo-electron tomography (cryo-ET), HDX, to name a few, have further enabled the toughest structural problems underlying disease biology. This newer "drug discovery centric" session aims to explore the latest advances and methodologies employed in the structure determination in the context of drug discovery. We will discuss the innovative approaches across drug discovery modalities, including covalent inhibitors, protein degraders, small molecules, and antibodies, antibody-scaffolds, etc., in industry and academia.

MS042 Biological mechanisms illuminated by cryoem and complementary methods in vitro

Co-Chairs: Melanie Ohi & John Rubinstein

SPONSORING COMMISSION: Biological Macromolecules

CryoEM complements X-ray crystallography in the study of biological mechanisms on the ångström scale and removes barriers to investigating macromolecules that are challenging to crystallize. Its capacity to visualize fine structural details and conformational flexibility in biological macromolecules extracted from cells or tissues provides important insights into the underpinnings of life and disease. The growing use of cryoEM in structural biology has led to nearly half of the structures deposited in the PDB in 2024-2025 being determined using cryoEM approaches. This microsymposium will present select findings from structural biologists worldwide who leverage the power of cryoEM to study biological macromolecules.

MS043 Molecular magnets: new phenomena and applications

Co-Chairs: Yuko Hosokoshi & Matthew Cliffe

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Crystallography of Materials

Molecular-based magnets have generated intense interest in recent years because of the technological possibilities they suggest in the emerging field of molecular spintronics. These are materials that combine intrinsic properties of molecular solids, such as nanoscopic size, low density, synthetic versatility, and optical transparency, with one or more physical properties of practical utility. Among the properties that have stimulated the greatest interest are optical, electrical, and magnetic properties, whether cooperative (such as ferromagnetism or superconductivity) or non-cooperative (such as superparamagnetism or spin glass behavior). Recently, materials have been obtained that combine electric and magnetic properties (molecular multiferroics), optical and magnetic properties, and even magnetic properties in systems with intramolecular electron transfer. In these multifunctional materials, mutual influences or synergies between the properties involved may enable the development of nanoscopic devices such as molecular switches or spin filters.

MS044 Cocrystals for reaching the 17 SDGs: understanding assembly, structure, and properties

Co-Chairs: Marta Dudek & Teresa Duarte

SPONSORING COMMISSION: NMR Crystallography and Related Methods

CO-SPONSORING COMMISSION: Structural Chemistry

This microsymposium will explore the role of cocrystals in advancing the United Nations 17 Sustainable Development Goals (SDGs). Cocrystals offer properties that can address various global challenges. The microsymposium will cover innovative approaches to designing and synthesizing cocrystals, with a focus on their applications in sustainable energy, environmental remediation, and healthcare, linking structural and dynamic features of these materials with their applications. It will also provide a forum for exchanging ideas on different characterization tools, including diffraction, thermal methods, NMR, and computational approaches. In addition, the microsymposium will highlight methodological advances in understanding phase transformations, salt-cocrystal equilibria, and crystallization of organic solids using time-resolved and in situ NMR tools. Areas of interest include monitoring polymorphic transformations under realistic crystallization conditions in the presence of solvents and/or elevated temperature, understanding mechanisms of mechanochemical cocrystal synthesis, and combining this with information on self-assembly in both solid and solution states. This will provide insights into crystal growth processes from the molecular to the macroscopic scale, leading to materials with targeted functions and properties as well as the rational design of cocrystallization.

MS045 Open data, standards, and repositories for small- and wide-angle X-ray and neutron scattering data in the era of big data and ai advancements

Co-Chairs: Estella Yee & Cy Jeffries

SPONSORING COMMISSION: Small Angle Scattering

In the age of rapidly expanding and increasingly complex X-ray and neutron scattering datasets, there is a growing need to present standardized data and metadata accurately, following modern best practices and adhering to the Findable, Accessible, Interoperable, and Reusable (FAIR) principles. This microsymposium will focus on the challenges and successes of open data formats and accessibility in the context of small- and wide-angle scattering experiments. Topics will include community-driven initiatives ranging from the formulation of basic reporting guidelines and measurement standards to the more complex tasks of packaging and disseminating intricate multimodal data and parameters. Discussions will also explore the role of beamlines and other sources in data storage and metadata production, enabling interoperable exchange across large-scale data resources and knowledge bases.

MS046 Mathematical and theoretical crystallography: insights into aperiodic phases and structures

Co-Chairs: Nobuhisa Fujita & Louise Antonette N. De las Penas

SPONSORING COMMISSION: Aperiodic Crystals

CO-SPONSORING COMMISSION: Mathematical and Theoretical Crystallography

This microsymposium will explore the interplay between mathematics and aperiodic order in materials, highlighting mathematical concepts such as symmetry and tiling theory that are crucial for understanding the complex atomic arrangements of aperiodic phases, including quasicrystals. These unique structures, in turn, offer fertile ground for mathematical exploration, inspiring new theoretical developments. By bringing together experts in crystallography, mathematics, and modeling, this microsymposium will highlight recent advances in the field and foster interdisciplinary discussions on aperiodic order and related structural complexity. The synergy between these disciplines promises to generate stimulating exchanges, advancing both theoretical insights and fundamental understanding of related materials.

MS047 Catalysis for net zero transition

Co-Chairs: Debora Meira & Adam S. Hoffman

SPONSORING COMMISSION: XAFS

SUPPORTING COMMISSION: Powder Diffraction

Mitigating global climate change requires new approaches to energy conversion through low-carbon catalytic processes, improved energy efficiency, and the use of clean energy sources. Discovering efficient catalytic systems demands a better understanding and control of the nature and behavior of catalytic sites. X-ray absorption spectroscopy (XAS), with its atomic selectivity and high sensitivity, provides powerful information on the oxidation state, local coordination environment, and atomic structure around the absorber at the scale of a few ångströms. The high penetration depth of hard X-rays further offers unique capabilities for designing catalytic reactors and studying catalysts under operando conditions. Combined with advanced methods such as modulation excitation spectroscopy (MES) or MCR-ALS multivariate analysis, active or intermediate species formed during catalytic processes can be isolated. This microsymposium will provide an overview of the broad applications of XAS in understanding catalysts used for the net-zero transition, including those in heterogeneous catalysis, electrocatalysis, and photocatalysis.

MS048 Measuring stress across length-scales using diffraction microstructure imaging

Co-Chairs: Levente Balogh & Jonathan Wright

SPONSORING COMMISSION: Diffraction Microstructure Imaging

CO-SPONSORING COMMISSION: Neutron Scattering

SUPPORTING COMMISSION: Powder Diffraction

Stresses in crystalline materials arise from multiple length scales, including crystallographic defects and defect structures at the nanoscale, grain and phase interactions at the mesoscale, and applied loading and residual stresses at the continuum scale. X-ray and neutron diffraction have been the primary tools for non-destructively characterizing elastic strains and stresses for nearly 100 years, but efforts have focused primarily on nanoscale (microstresses) and continuum-scale characterization, while the mesoscale has often been neglected. Diffraction microstructure imaging (DMI) addresses this length-scale gap. This microsymposium will highlight recent research using DMI techniques to measure elastic strain and stress, with a focus on diffraction-based measurements that span multiple length scales or validate stress measurements and modeling results with different diffraction-based approaches.

MS049 COFs and HOFs: design, crystal growth, and applications

Co-Chairs: Dinesh Shetty & Ichiro Hisaki

SPONSORING COMMISSION: Structural Chemistry

Covalent organic frameworks (COFs) and hydrogen-bonded organic frameworks (HOFs) are porous materials that have attracted significant attention in recent years. These materials exhibit highly ordered structures and tunable porosity, making them promising for a wide range of applications. Recent advances in COF research include direct air capture (DAC) of CO₂, macroscopic developments of 3D COFs, conductive COFs, environmental applications, and catalysis. Advances in HOF research include stable HOF architectures and their applications, high-performance photocatalysts for hydrogen evolution, and hetero-architectures of HOFs. These studies highlight the growing potential of COFs and HOFs as functional materials, paving the way for further developments in the field.

MS050 Machine learning in low-resolution crystallographic computing

Co-Chairs: Nick Furnham & Senik Matinyan

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: Biological Macromolecules

Low-resolution crystallographic data present unique challenges in structural determination, requiring innovative computational approaches to extract meaningful insights. Traditional methods often struggle with the ambiguity and noise inherent in such datasets, leading to incomplete or inaccurate models. Machine learning (ML) has emerged as a powerful tool to address these challenges by leveraging large datasets to identify patterns, enhance electron density map interpretation, and predict missing structural information. ML techniques such as convolutional neural networks (CNNs) and generative models are being applied to improve map sharpening, feature recognition, and model building in low-resolution crystallography, while reinforcement learning algorithms are aiding in optimizing refinement strategies and model validation. Integrating ML into low-resolution crystallographic computing enhances the accuracy, speed, and reproducibility of structural analyses, enabling researchers to extract insights from previously intractable data. This microsymposium will explore the latest advancements in ML-driven approaches, their applications in refining low-resolution structures, and the future prospects of combining artificial intelligence with conventional crystallographic workflows to overcome the limitations of low-resolution data.

MS051 Current trends in structure-guided drug discovery II

Co-Chairs: Aled Edwards & Christine Carbone

SPONSORING COMMISSION: Biological Macromolecules

Unraveling structural mechanisms of drug action and advancing rational drug design has been at the forefront of drug discovery and development for decades, owing particularly to crystallography and NMR techniques. Modern high-resolution structural biology methods such as cryo-EM, cryo-electron tomography (cryo-ET), and HDX have further enabled solutions to some of the most challenging structural problems underlying disease biology. This drug discovery-centric microsymposium will explore the latest advances and methodologies employed in structure determination in the context of drug discovery. Topics will include innovative approaches across drug discovery modalities such as covalent inhibitors, protein degraders, small molecules, antibodies, and antibody scaffolds in both industry and academia.

MS052 Biological mechanisms illuminated by cryoET and complementary methods in situ

Co-Chairs: Stefan Raunser & Liz Wright

SPONSORING COMMISSION: Biological Macromolecules

CryoEM makes it possible to observe biological macromolecules directly in their native cellular context. This rapidly growing field blurs the boundaries between atomic-scale structural biology and organelle-scale cellular biology by leveraging tomography, subtomogram averaging, template matching, and other technologies that are still under active development.

MS053 Altermagnetic, topological, and other unconventional magnetic materials and phenomena

Co-Chairs: Libor Smejkal & Tomas Jungwirth

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Powder Diffraction

SUPPORTING COMMISSION: Crystallographic Computing

This microsymposium is dedicated to exploring new classes of magnets, including altermagnets and topological materials, which are difficult to understand solely on the basis of a diffraction pattern. These materials exhibit unique properties and require updated perspectives on magnetic symmetry and advanced characterization tools. Topologically equivalent states are connected through continuous deformation and remain protected against perturbations; such states can arise in both magnetic configurations and electronic structures. Altermagnets feature collinear, compensated magnetic sublattices that are related by rotation rather than translation or inversion, leading to non-relativistic spin-split bands.

MS054 Functional thin films: crystallography’s next frontier

Co-Chairs: Rebecca Smaha & Daniel Sando

SPONSORING COMMISSION: Crystallography of Materials

CO-SPONSORING COMMISSION: Powder Diffraction

SUPPORTING COMMISSION: Magnetic Structures

This microsymposium will focus on the structural characterization of functional thin films that are critical to energy and quantum technologies, both as prepared and under external stimuli. Topics include catalysis, solar energy materials, semiconductors, piezoelectrics and ferroelectrics, as well as materials for quantum information science and spintronics.

MS055 (Ultra) small angle scattering approaches to hierarchy across structural science

Co-Chairs: Jan Ilavsky & Josefine Eliso Nielsen

SPONSORING COMMISSION: Small Angle Scattering

Biological studies, including crystallography, often depend on hierarchical assembly, beginning with soluble molecules that ultimately organize into reactive macroscopic materials. Understanding these assemblies and the processes that drive their formation requires the application of multiple techniques that traverse different length scales. Ultra-small-angle scattering (USAS) is an indispensable tool for in situ observation and characterization of hierarchical structures from the nanoscale to the micrometer scale, which is important for understanding the dynamic processes that control materials. This microsymposium will explore exemplary material systems, from biological to metallic, where hierarchical structure characterization is critical, as well as the methods used to characterize their assembly.

MS056 Combining complementary techniques in quantum crystallography

Co-Chairs: Kenji Tsuda & Paulina Dominiak

Invited Speakers: Martin Dračínský, Colin Ophus & Yoshiharu Sakurai

SPONSORING COMMISSION: Quantum Crystallography

CO-SPONSORING COMMISSION: Electron Crystallography

SUPPORTING COMMISSION: NMR Crystallography and Related Methods

No single technique can fully provide all the quantum crystallographic information desirable from a material or molecule. Time and again, the importance of combining different crystallographic techniques, both experimental and theoretical, has been demonstrated in bridging knowledge gaps when relating quantum crystallographic observables and electron, spin, and momentum densities to material properties. This microsymposium will seek contributions from researchers combining experimental and theoretical approaches to extract broader ranges of quantum crystallographic information.

MS057 Compositionally complex materials: challenges and opportunities for X-ray absorption, pair distribution function, and related probes

Co-Chairs: Dibyendu Bhattacharyya & Ben Frandsen

SPONSORING COMMISSION: XAFS

CO-SPONSORING COMMISSION: Powder Diffraction

Compositionally complex materials exhibit tremendous promise for the development of new materials with superior properties compared to conventional materials. Perhaps the most well-known are high-entropy materials (HEMs), which are composed of multiple principal elements (five or more), leading to high configurational entropies that can stabilize single-phase structures, even at high temperatures. Medium-entropy materials have also recently emerged as promising systems for materials development. The so-called “cocktail effect” of the multiple component elements often produces exceptional mechanical, thermal, optical, magnetic, and chemical properties, leading to various important functionalities, including enhanced catalytic and energy storage properties. Characterization of these materials in an element-specific manner with sensitivity to local structure provides valuable insights into the dependence of their properties on each chemical component. This is a challenging task that requires advanced techniques such as X-ray near-edge spectroscopy (XANES), extended X-ray absorption spectroscopy (EXAFS), pair distribution function analysis, and more. This microsymposium will highlight recent advances in the structural study of compositionally complex materials, establish future research directions, and discuss technical developments that enable deeper understanding of these important materials.

MS058 Best practices for X-ray, neutron and electron data processing and reuse

Co-Chairs: Aaron Brewster & Christine Beavers

SPONSORING COMMISSION: CommDat

CO-SPONSORING COMMISSION: Electron Crystallography

Data collection volume and velocity has increased vastly, even considering the last 5-10 years. High throughput, serial and electron crystallography are but a few examples of techniques which not only produce high volumes of data and results quickly but also challenge our notions of quality and definitive results. These challenges with data processing and workup relate to simply "keeping up," as well as how to generate the best possible quality results and what they are suitable to be used for. Knock-on consequences also exist for reuse and data-driven science, with potential to populate databases with variable results and suitability questions for follow-on work such as training AI models. Driven by practical examples and (evolving) best practices, this general interest microsymposium will consider the data challenges we currently face ranging from raw data processing through refinement, quality, raw data archiving & reuse to validity in data science

MS059 Using crystallographic databases for data exploration and exploitation

Co-Chairs: Daumantas Matulis & Anuradha Pallipurath

SPONSORING COMMISSION: Structural Chemistry

CO-SPONSORING COMMISSION: CommDat

The rise of artificial intelligence (AI) and machine learning (ML) has the potential to transform scientific research, and central to the successful implementation of such models in our community is access to high-quality structural data. This microsymposium will highlight the application of crystallographic databases in AI/ML approaches to explore and address challenges in structural chemistry.

MS060 Single-crystal-to-single-crystal transitions: mechanisms, cooperativity, applications

Co-Chairs: Roberto Centore & TBD

SPONSORING COMMISSION: Structural Chemistry

The peculiar nature of single-crystal-to-single-crystal (SCSC) transitions within the realm of solid-state transformations has long been recognized and debated in the literature from different perspectives. The increasing amount of experimental data on SCSC transitions, now available due to intensive research on dynamic crystals in recent years, calls for a reexamination of the mechanisms underlying these transformations.

MS061 Structure-guided protein design/engineering in biomedicine and biotechnology I

Co-Chairs: Igor Polikarpov & Vanita Sood

SPONSORING COMMISSION: Biological Macromolecules

Structure-guided protein design and engineering are opening new frontiers in biomedicine and biotechnology by enabling the creation of molecules with functions not represented in nature. Approaches such as inverse folding, backbone design, protein inpainting, scaffolding for designed active sites, and engineering protein surfaces for binding or catalysis are driving innovation in biologics and therapeutic proteins. This microsymposium will highlight recent advances in computational design, experimental strategies, and structural characterization that expand the boundaries of molecular functionality, demonstrating how engineered proteins can address challenges in medicine, biotechnology, and materials science.

MS062 Approximate periodic symmetry

Co-Chairs: Carolyn Brock & John Evans

Invited Speakers: Toms Rekis, Inbal Tuvi-Arad & Kraig Wheeler

SPONSORING COMMISSION: Crystallographic Nomenclature and the International Tables

Approximate symmetry that is periodic has long been recognized, but its prevalence, revealed through database studies, has only recently been appreciated. Approximate periodic symmetry is found in structures determined below a phase transition and in enantiopure crystals that mimic centrosymmetric packing. It also appears in many other crystals that may have nucleated in a space group of higher symmetry and then become distorted during growth. Algorithms for identifying and quantifying approximate symmetry are being developed, but trained eyes remain very useful. Applications include the design of noncentrosymmetric and polar crystals, the identification of structural families of related materials, and the investigation of phase transitions.

MS063 Recent advances in optical floating zone growth

Co-Chairs: Satya Kushwaha & Arvind Yogi

Invited Speakers: Geetha Balakrishnan & Stephen Wilson

SPONSORING COMMISSION: Crystal Growth and Characterization of Materials

Floating zone (FZ) methods provide avenues to grow single crystals with ultrahigh purity, essential for next-generation materials research and technologies. Recently, infrared lasers have been introduced as a heat source and, unlike traditional optical FZ, they provide greater flexibility in operation and more controlled molten zones. In laser FZ, enormous energy can be concentrated in a small volume, allowing the creation of exceptionally high temperatures exceeding ~4000 °C and enabling higher operating pressures. Such high temperatures and pressures have opened the door to next-generation materials synthesis capabilities and provide opportunities for discovering new materials that were previously inaccessible, such as high-valency metal oxides and ultrahigh-temperature ceramics, in a more economical way.

MS064 Quantum crystallography of magnetism, bonding, and spin densities

Co-Chairs: Huibo Cao & William Ratcliff

SPONSORING COMMISSION: Quantum Crystallography

CO-SPONSORING COMMISSION: Structural Chemistry

SUPPORTING COMMISSION: Magnetic Structures

Combining different techniques spanning the radiations used in crystallography can provide insights into phenomena such as the interplay between charge and spin density waves in kagome metals and superconductors, metal-insulator transitions, charge ordering, magnetism, superconductivity under high pressure, symmetry-breaking mechanisms, lattice distortions, electronic topology, and the discovery of novel quantum materials. This microsymposium welcomes contributions across this broad range of important research topics.

MS065 X-ray spectroscopy: high energy resolution methods

Co-Chairs: Amélie Juhin & Gerry Seidler

SPONSORING COMMISSION: XAFS

CO-SPONSORING COMMISSION: Synchrotron and XFEL Radiation

SUPPORTING COMMISSION: Quantum Crystallography

High-energy-resolution X-ray spectroscopy has revolutionized our ability to probe electronic and structural properties in materials, providing unprecedented insights into their fundamental behavior. Techniques such as high-resolution X-ray absorption spectroscopy (HR-XAS), resonant inelastic X-ray scattering (RIXS), and X-ray emission spectroscopy (XES) allow researchers to explore valence states, electronic excitations, and chemical environments with exceptional precision. These methods are essential for understanding a wide range of materials, from catalysts and energy storage systems to quantum materials and biological systems. With advancements in synchrotron and free-electron laser sources, as well as improvements in spectrometer designs and data analysis, the field is pushing the limits of energy resolution, signal detection, and time-resolved capabilities. This microsymposium will bring together experts to discuss the latest developments in instrumentation, methodologies, and applications of high-energy-resolution X-ray spectroscopy, highlighting its impact across various scientific disciplines.

MS066 Sustainability of heritage materials and buildings

Co-Chairs: Miguel Delgado & Klaudia Hradil

SPONSORING COMMISSION: Crystallography in Art and Cultural Heritage

Sustainability has become an increasingly important concept in response to the growing challenges of climate change and environmental degradation. Within the cultural heritage community, the maintenance and restoration of cultural objects and sites has always been a priority, but new threats such as air pollution, wildfires, floods, and human conflicts are accelerating deterioration processes. Understanding these processes and developing effective solutions to slow, halt, or reverse them is essential. Equally important is the sharing of knowledge and best practices with the global community to strengthen collective efforts to safeguard cultural heritage.

MS067 Discrete organic/coordination cages: design and applications

Co-Chairs: Shuhei Furukawa & Guido H. Clever

SPONSORING COMMISSION: Structural Chemistry

In recent years, research on discrete organic cages (DOCs) and coordination cages has advanced rapidly. These cage structures hold great potential for applications in catalysis, molecular recognition, drug delivery, and more. Current research trends include applications in energy-related fields, biomedical uses of coordination cages, dynamic transformation and self-assembly, catalytic reactions inside coordination cages, and the structural design and control of self-assembly. These studies highlight the diverse applications and potential of discrete organic and coordination cages, promising further advancements in the field.

MS068 How to use predicted models effectively: methodologies and case studies

Co-Chairs: Dorothee Liebschner & Omid Haji-Ghassemi

SPONSORING COMMISSION: Crystallographic Computing

This microsymposium will explore best practices for using predicted models in structural biology, including combining them with experimental data, assessing reliability and accuracy, and incorporating them into structure determination workflows. Case studies may showcase successful applications such as the interpretation of cryo-EM maps, structure-guided drug discovery, the determination of multiprotein complex structures, and hybrid modeling approaches that combine AlphaFold predictions with SAXS and NMR data. With recent breakthroughs in protein structure prediction, particularly through tools like AlphaFold2/3 and RoseTTAFold, structural biologists now have access to highly accurate predicted models. However, effectively integrating these models into experimental workflows requires an understanding of best practices and a reevaluation of traditional structure determination approaches.

MS069 Crystallography of solid-state ionic conductors

Co-Chairs: Ivana Evans & Maths Karlsson

SPONSORING COMMISSION: Inorganic and Mineral Structures

CO-SPONSORING COMMISSION: Powder Diffraction

SUPPORTING COMMISSION: Crystallography of Materials

The search for new and improved solid-state ionic conductors (SSICs) is one of the most active fields in materials chemistry, driven by their key role in technologies such as solid-state batteries, fuel cells, sensors, carbon capture compounds, and hydrogen storage. Solid-state ionic conduction is also a crucial aspect of mineral formation, subsolidus synthesis, and post-synthetic modification in materials chemistry. This microsymposium will cover structural aspects of solid-state ionic conduction, emphasizing the insights obtained through crystallographic analysis and the progress enabled by applying crystallographic design principles. Topics include lithium, proton, oxide, and other mobile ions; hydration and carbonation in geological and technological contexts; associated phase transitions and symmetry analysis; computational simulations; and in situ/operando experiments using diffraction and related methods.

MS070 Serial crystallography

Co-Chairs: Pierre Aller & Aina Cohen

SPONSORING COMMISSION: Synchrotron and XFEL Radiation

Serial crystallography has become a standard method for structure determination at light sources worldwide. Far from its early days of experimental uncertainty and bootstrap methods, the field has matured, with well-defined applications that leverage the advantages of low-dose, highly redundant data collection. These applications range from time-resolved crystallography to small-molecule structure determination and beyond. However, significant challenges remain interoperability between facilities, instrumentation, and software continues to be a bottleneck, as does improving accessibility for the broader structural biology community. This microsymposium will explore the latest progress in all aspects of serial crystallography, including advancements in hardware, algorithms, user programs, and results from groundbreaking experiments.

MS071 Structure-guided protein design/engineering in biomedicine and biotechnology II

Co-Chairs: Soichi Wakatsuki & Sagar Khare

SPONSORING COMMISSION: Biological Macromolecules

The application of structural biology-based strategies for drug discovery has a longstanding record, leading to the development of numerous therapeutic agents. The field’s potential extends far beyond drug design. This microsymposium will showcase a diverse and innovative range of structural biology applications, particularly those linked to the tremendous progress in protein engineering that combines state-of-the-art experimental approaches with cutting-edge computational methods.

MS072 Methods for the determination and analysis of magnetic structures from powders and single crystals

Co-Chairs: JM Perez-Mato & Margarida Henriques

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Powder Diffraction

SUPPORTING COMMISSION: Neutron Scattering

The aim of this microsymposium is to demonstrate the potential of magnetic diffraction when combined with advanced analytical tools such as magnetic symmetry groups and representation analysis. It will cover new methods and developments for the determination of magnetic structures, while also welcoming experimental contributions where the method used to determine the magnetic structure is itself of significant interest.

MS073 Diffuse scattering and dynamics in complex systems and disordered materials

Co-Chairs: Arkadiy Simonov & Arianna Minelli

SPONSORING COMMISSION: Crystallography of Materials

CO-SPONSORING COMMISSION: Aperiodic Crystals

Understanding the interplay between disorder and dynamics is crucial for uncovering the fundamental properties of complex materials. Diffuse scattering is a powerful tool for capturing short-range correlations, local distortions, and dynamic phenomena across a wide range of materials. Recent advancements in diffuse scattering experimental methods, coupled with computational modeling and machine learning, have created new opportunities to decode complex disordered structures and their influence on material behavior. This microsymposium will highlight recent advances in diffuse scattering techniques and discuss how to bridge the gap between atomic-scale understanding of disorder and macroscopic properties. Topics will include recent developments in data collection, interpretation, and modeling, and their application to next-generation functional materials.

MS074 In-situ studies of materials synthesis and crystal growth

Co-Chairs: Matteo Bianchini & Andrea Kirsch

SPONSORING COMMISSION: Powder Diffraction

CO-SPONSORING COMMISSION: Neutron Scattering

Chemical synthesis and processes are critical in everyday life, from functional materials to pharmaceuticals to high-performance computing components. These reactions can proceed through a variety of crystalline or amorphous intermediates before yielding the final product. Understanding and monitoring synthesis under real-world conditions provides valuable insights for industrial applications. This has been enabled by the development of ancillary equipment adapted to diffractometers and scattering instruments that simulate real-world conditions, allowing the tracking of crystalline and other components as a function of synthesis parameters such as reaction time, temperature, and atmosphere. Such data provide guidance on the optimal conditions for obtaining the desired phase, which in turn can inform improved synthesis protocols. With this information, industry can optimize procedures while minimizing reaction times and costs.

MS075 Structure visualization techniques for teaching

Co-Chairs: Nichole Valdez & Nico Graw

SPONSORING COMMISSION: Crystallographic Teaching

CO-SPONSORING COMMISSION: Magnetic Structures

One of the most challenging elements of teaching structural science is communicating three-dimensional (3D) concepts in a classroom setting. This microsymposium will highlight technique development and advancements in visualization technologies that allow instructors and students to explore crystallographic concepts and structural data in helpful and engaging ways. Submissions are invited on a broad spectrum of visualization tools and technologies showcasing both high- and low-tech solutions, including classroom activities, physical models or model kits, animation and rendering techniques, effective diagram design, lighting and coloring strategies, computer-aided design (CAD), virtual reality (VR), augmented reality (AR), and 3D printing. Good visualization strategies are not limited to the classroom, and this microsymposium will also promote cross-disciplinary exchange and highlight the central role visualization plays in advancing and effectively communicating crystallographic research. Contributions from all disciplines are welcome.

MS076 Integrative structural chemistry and biology: the power of combining data

Co-Chairs: Massimiliano Bonomi & Ignacia Echeverria

SPONSORING COMMISSION: CommDat

CO-SPONSORING COMMISSION: Biological Macromolecules

Integrative structural biology leverages data from X-rays, neutrons, and electrons, combined with AI-driven predictions, to provide a comprehensive and accurate view of biological macromolecules. However, differences in resolution, contrast mechanisms, and experimental conditions pose significant challenges for data integration. Resolution reflects spatial detail, while contrast depends on signal-to-noise ratios and scattering properties. Errors may arise from experimental limitations, data processing, and model assumptions, necessitating rigorous validation and refinement strategies. AI plays a crucial role in aligning heterogeneous datasets, predicting missing structural elements, and identifying inconsistencies. Developing robust methodologies for merging multimodal data will be essential for advancing our understanding of complex biological systems, such as the nuclear pore complex or ribosome dynamics.

MS077 Polymorphism and isostructurality of molecular crystals: from fundamentals to applications

Co-Chairs: Antonio Carlos Doriguetto & Luca Catalano

SPONSORING COMMISSION: Structural Chemistry

Polymorphism—the existence of multiple crystal forms of the same compound—is a fundamental yet not fully understood phenomenon with far-reaching implications, from academic research to real-world applications. The exploration of the structural background of isostructurality—highly similar molecular arrangements in crystals of chemically different compounds—brings us closer to advancing crystal engineering. This microsymposium will bring together experts from academia and industry to discuss isostructurality, polymorphism, and phase transitions, covering molecular and mechanistic perspectives as well as their impact on industrial processes and applications, including drug development, organic electronics, and food chemistry.

MS078 Structural studies across time scales: experimental and computational advances in time-resolved crystallography

Co-Chairs: Keith Moffat & Thomas Ursby

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: Biological Macromolecules

SUPPORTING COMMISSION: Synchrotron and XFEL Radiation

Time-resolved crystallography has revolutionized our ability to capture dynamic structural changes in biological macromolecules and materials, providing insights into molecular mechanisms across different time scales. Advances in computational methods have been instrumental in processing and interpreting large-scale time-resolved crystallographic datasets, enabling high-resolution structural determination from femtoseconds to seconds. The development of sophisticated algorithms and data-processing pipelines has facilitated the integration of serial crystallography techniques at synchrotron and X-ray free-electron laser (XFEL) facilities, where the rapid collection of thousands of diffraction images presents unique challenges in data handling, synchronization, and model refinement. Computational approaches such as real-time feedback systems, machine learning-driven data reduction, and multidimensional modeling are driving improvements in accuracy and efficiency. The future of time-resolved crystallography lies in the synergy between experimental innovation and computational advancements, paving the way for a deeper understanding of dynamic processes in biological and materials sciences.

MS079 Advances in electron crystallography methods

Co-Chairs: Louisa Meshi & Lukas Palatinus

SPONSORING COMMISSION: Electron Crystallography

Electron diffraction is currently in a lively period of advancement, with many novel methods being developed. Recently, there has been a shift toward studying smaller and more beam-sensitive crystals at increasingly higher levels of detail. This progress has been enabled by new diffraction methods requiring advanced experimental procedures such as electron beam scanning, crystal tracking, and 4D-STEM. This microsymposium is devoted to the novel hardware and software being developed to push electron diffraction and electron crystallography beyond previous limits. With recent advancements in dedicated electron diffractometers and 4D-STEM instrumentation, electron diffraction is expanding to more laboratories worldwide, attracting a growing audience directly interested in these developments. This microsymposium will focus on the latest methodological advances in electron crystallography.

MS080 Spectroscopy meets imaging

Co-Chairs: Helio Tolentino & Chanh Tran

SPONSORING COMMISSION: Synchrotron and XFEL Radiation

CO-SPONSORING COMMISSION: XAFS

SUPPORTING COMMISSION: Biological Macromolecules

The convergence of spectroscopy and imaging techniques is revolutionizing our ability to probe the chemical, electronic, and structural properties of materials and biological systems. By integrating high-resolution spectroscopic methods with advanced imaging modalities, researchers can now achieve unprecedented spatial and spectral insights across a wide range of scientific disciplines. This microsymposium will explore the latest developments in multimodal approaches that combine X-ray, electron, and optical spectroscopies with imaging techniques such as holography, ptychography, tomography, and fluorescence mapping. It will highlight recent breakthroughs in instrumentation, data processing, and applications in materials science, catalysis, environmental science, and life sciences.

MS081 Innovations in cryoEM and cryoET

Co-Chairs: Wei Dai & Genji Kurisu

SPONSORING COMMISSION: Biological Macromolecules

This microsymposium will highlight 21st-century approaches to structural enzymology, showcasing how high-resolution crystallography, neutron diffraction, high-resolution cryo-EM, and integrative and computational methods are being applied to elucidate enzyme mechanisms and functions. It will also include topics on protein flexibility and dynamics, emphasizing how conformational changes, dynamic behavior, and structural adaptability contribute to enzymatic activity. By bringing together diverse experimental and computational perspectives, the session will illustrate how modern structural biology is advancing our understanding of enzyme function in unprecedented detail.

MS082 Innovations in algorithms and computational methods in crystallography

Co-Chairs: Isabel Uson & Garib Murshudov

SPONSORING COMMISSION: Biological Macromolecules

This microsymposium will cover the latest innovations in algorithms and computational methods in crystallography, including advances in model-building software, automation strategies, and best practices for interpreting density maps. It will also address structure solution and refinement techniques for challenging datasets, such as low-resolution diffraction, poorly ordered crystals, and flexible macromolecular complexes. In addition, the session will highlight emerging approaches that integrate machine learning, hybrid modeling, and cross-validation strategies to improve accuracy and reliability, illustrating how computational innovation is transforming modern crystallographic practice.

MS083 Crystal growth and development of optical crystals for medical applications

Co-Chairs: Mariya Zhuravleva & Philippe Veber

SPONSORING COMMISSION: Crystal Growth and Characterization of Materials

This microsymposium will highlight recent advances in the growth and development of optical crystals for medical applications. Contributions are expected on novel scintillator crystals for medical imaging techniques, including computed tomography (CT), positron emission tomography (PET), positron emission mammography (PEM), and single-photon emission computed tomography (SPECT), as well as on laser crystals for surgical devices. The session will showcase new materials, growth methods, and characterization strategies, emphasizing which of the latest developments hold the greatest promise for future medical applications.

MS084 Quantum crystallography of non-equilibrium or nanostructured materials

Co-Chairs: Anna Makal & Eiji Nishibori

SPONSORING COMMISSION: Quantum Crystallography

CO-SPONSORING COMMISSION: Magnetic Structures

Real materials are neither perfect crystals nor “ideally imperfect” crystals. They are affected by temperature and pressure and contain defects and nanostructures, all of which influence their properties. This microsymposium welcomes contributions on high-pressure crystallography, disordered materials, lattice dynamics, diffuse scattering, interrogation of defects and nanostructures, and the crystallography of excited states, as well as studies of other systems that differ from single-phase, ideal crystals. Such investigations push quantum crystallography toward the measurement of bonding, spin, and momentum densities in unconventional but truly “real” material systems.

MS085 Neutron and X-ray contrast variation methods in small angle scattering, their application and synergy

Co-Chairs: Armin Hoell & Volker Urban

SPONSORING COMMISSION: Small Angle Scattering

CO-SPONSORING COMMISSION: Neutron Scattering

This microsymposium will focus on contrast variation methods in small-angle scattering using X-rays, neutrons, or both to analyze complex multicomponent nanostructures in scientific and technical applications. It will address the disentanglement of complex problems in chemistry, physics, biology, materials science, and catalyst research, including critical phenomena, kinetics of phase transitions, self-assembly, transport phenomena, and catalytic activity. The session will also cover theoretical and methodological aspects and the complementary use of neutrons and X-rays in small-angle scattering.

MS086 X-ray spectroscopy for biological systems

Co-Chairs: Irene Diaz-Moreno & Kajsa Sigfridsson Clauss

SPONSORING COMMISSION: XAFS

CO-SPONSORING COMMISSION: Biological Macromolecules

X-ray absorption spectroscopy (XAS) has traditionally been used to determine the local geometrical environment and electronic structure of metal-containing biological systems such as proteins and enzymes. This knowledge, complementary to information obtained with other structural techniques such as crystallography, has been essential for understanding the function of these systems. In recent years, photon-in/photon-out techniques such as resonant and non-resonant X-ray emission spectroscopies (RXES and XES), as well as high-energy-resolution fluorescence-detected XAS (HERFD-XAS), have expanded the X-ray spectroscopy toolkit for investigating chemically specific electronic and geometrical structures. These techniques have been applied to biologically relevant processes, such as small-molecule binding and activation in different ligand protonation states, or the identification of bridging oxo groups in the Mn₄Ca cluster of photosystem II. This microsymposium will bring together experts to provide an overview of novel developments in X-ray spectroscopy that are offering unprecedented insights into biological systems.

MS087 Service crystallography: operations and applications

Co-Chairs: Alejandro Ayala & Vojtech Jancik

SPONSORING COMMISSION: Structural Chemistry

This microsymposium will cover the topic of service crystallography, focusing on specialized facilities that provide expert X-ray crystallographic analysis to academic and industrial researchers. Presentations will detail the operational aspects of these core facilities, including sample handling, data collection, and structure determination for a diverse user base. The session will also examine the application of this service model in key scientific areas such as drug discovery, chemical synthesis, and materials science.

MS088 Computing with graphs and topological indices

Co-Chairs: Martin Lutz & Greg McColm

Invited Speakers: Olga Anosova, Mohamed Eddaoudi & Sergie Grudinin

SPONSORING COMMISSION: Crystallographic Computing

Graph sets (Etter) and topological indices (Wells) have a long history in the description of organic and inorganic structures, especially crystal structures. At times, their predictive power has been questioned, but the situation has fundamentally changed with the advent of machine learning, which is highly compatible with these descriptors. This microsymposium will showcase the latest applications and provide a platform for presenting needed algorithms, such as the Euler characteristic.

MS89 Diffuse scattering and 3D-PDF: unveiling hidden order in single crystals

Co-Chairs: Guilherme Calligaris & Reinhard B. Neder

SPONSORING COMMISSION: High Pressure

Diffuse scattering is a pivotal technique for investigating local disorder and correlations across diverse disciplines. In quantum materials, it elucidates symmetry breaking and electronic correlations essential for superconductors and functional oxides. In structural chemistry, it offers insights into vacancy networks and dynamic disorder in hybrid materials. In biology, it advances the understanding of correlated motions in proteins and enzyme mechanisms. The application of three-dimensional pair distribution function (3D-PDF) analysis and its variations has expanded the study of single-crystal diffuse scattering, enabling precise characterization of complex disorder and local correlations. This microsymposium will highlight the latest advancements in this field and assess its potential future applications, including compatibility with non-ambient conditions (such as high pressure and low temperature) and its interdisciplinary nature.

MS090 IUCr purpose, vision and values

Co-Chairs: Hanna Dabkowska & Santiago Garcia-Granda

SPONSORING COMMISSION: IUCr Early Career Scientist Division

The IUCr Executive Committee initiated a process of reflection to redefine the Purpose, Vision, and Values that characterize the Union and shape its strategies and image as a global scientific organization. This process, launched at the 26th Congress and General Assembly in Melbourne at the initiative of Professor Jenny Martin, has since been adopted by the IUCr, with initial results enabling the redefinition of its identity through the involvement of the entire community of structural scientists. This session will present the community’s contributions to this process and discuss the directions the Union should take in consolidating its position as a representative of structural science in both academic and social contexts. Topics will include sustaining the impact of outreach and education programs to ensure engagement of future generations, responding to challenges of diversity and inclusion, addressing sustainability, and ensuring structural science contributes to societal needs with equity, honesty, truth, and scientific rigor. Key issues, risks, opportunities, and needs for the future of the Union will be discussed, with particular focus on generational renewal, attracting young scientists, and ensuring financial sustainability. The entire structural science community is encouraged to submit ideas.

MS091 Current advances and methodologies in membrane protein structural biology

Co-Chairs: Shaker Chuck Farah & M. Joanne Lemieux

SPONSORING COMMISSION: Biological Macromolecules

Membrane proteins play a crucial role in numerous biological processes and are increasingly recognized as important therapeutic targets for drug discovery and development. However, their structural characterization presents unique challenges due to their hydrophobic nature, complex dynamics, and the difficulty in obtaining sufficient quantities of functional proteins. This microsymposium will explore the latest advances and methodologies in the structural determination of membrane proteins, including advanced detergent formulations for stabilization and purification, high-throughput crystallization, and cryo-EM. It will provide a platform for sharing knowledge, experiences, and strategies to advance membrane protein research, uncover new biology, and support drug discovery.

MS092 Exploring unconventional magnetic phenomena in geometrically frustrated magnets

Co-Chairs: Bruce Gaulin & Sylvain Petit

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Neutron Scattering

Geometrically frustratedor otherwise disordered magnetic materials provide a rich playground for discovering unconventional states of matter, where competing interactions prevent the system from adopting a simple ordered state. These materials give rise to a variety of exotic magnetic phases, including spin liquids, spin ices, multipolar orders, helimagnetism, spin-density waves, and topological spin textures such as skyrmions. Understanding these emergent behaviors is crucial for advancing fundamental condensed matter physics and for potential applications in spintronics and quantum information science. This microsymposium invites contributions on the synthesis and characterization of new frustrated materials, neutron and X-ray scattering investigations, thermodynamic and transport measurements, and theoretical modeling and simulations that shed light on frustration-driven phenomena. We also welcome studies exploring the role of frustration in stabilizing topological states, quantum magnetism, and novel field-induced phases. By bringing together experimentalists and theorists, this session aims to spark discussions on the latest discoveries and new directions in the field.

MS093 PDF (total scattering) experiments and local structure characterization of functional materials

Co-Chairs: TBD & Igor Levin

SPONSORING COMMISSION: Crystallography of Materials

CO-SPONSORING COMMISSION: Synchrotron and XFEL Radiation

SUPPORTING COMMISSION: Powder Diffraction

Emphasizing the synergy between pair distribution function (PDF) analysis, total scattering, and various spectroscopic techniques, this microsymposium will highlight recent advancements in probing local crystal structure, magnetic structure, and structural dynamics of powder and ceramic materials, and their relationship to bulk material properties.

MS094 Integrative approaches to biomacromolecular structure determination

Co-Chairs: Leonard J Mueller & Jill Chrencik

SPONSORING COMMISSION: NMR Crystallography and Related Methods

CO-SPONSORING COMMISSION: Biological Macromolecules

This microsymposium will explore how diverse experimental and computational techniques such as X-ray crystallography, cryo-EM, NMR, and small-angle scattering can be integrated to determine macromolecular structures. It will highlight recent developments in solving structures of different classes of biomolecules, including proteins, nucleic acids, and carbohydrates. Advances in solid-state NMR spectroscopy have enabled new insights into the structure, dynamics, and interactions of biomolecules, providing information complementary to that obtained by other methods. Recent applications emphasize the complementarity of solid-state NMR with other structural biology techniques, such as cryo-EM, solution-state NMR, and X-ray crystallography. Contributions may focus on best practices for combining data from different sources and resolving discrepancies, as well as case studies highlighting successful applications that integrate structural and dynamic information across a variety of time and length scales.

MS095 Balancing service for academia vs industry: the economics of crystallography

Co-Chairs: Nathaniel (Nate) Barker & Fabia Gozzo

SPONSORING COMMISSION: Crystallographic Teaching

Crystallography is vital across disciplines, yet the economics of sustaining laboratories differ greatly between academia and industry. Academic facilities depend on public funding and training mandates, while industry faces strict timelines, regulatory demands, and cost-effectiveness pressures. This microsymposium will examine how funding models, service priorities, and collaboration frameworks shape access, innovation, and long-term sustainability. By contrasting academic and industrial perspectives, it will highlight both challenges and opportunities in building economically viable crystallography services..

MS096 Structural characterization of amorphous solids, glasses and liquids (disordered materials)

Co-Chairs: Oliver Hammond & Chiara Maurizio

SPONSORING COMMISSION: XAFS

SUPPORTING COMMISSION: Powder Diffraction

The two archetypal classes of disordered materials are liquids and glasses. Liquids have no long-range order but display local correlations between molecules. Similarly, amorphous solids and glasses are not crystalline materials, i.e., they are solids without long-range order but still exhibit local order between atoms. The short-range sensitivity of XAS makes it ideal for studying disordered materials, while in total neutron scattering analysis the weak diffuse features are related to short- and medium-range order. This microsymposium will highlight the strengths and limitations, as well as the complementarity, of spectroscopic and scattering techniques for understanding the structural correlations at the atomic and molecular scale that underpin the macroscopic properties of disordered materials.

MS097 Crystallographic approach to mechanochemistry

Co-Chairs: Adam A. L. Michalchuk & Ivan Halasz

SPONSORING COMMISSION: Structural Chemistry

This microsymposium will discuss recent progress in understanding mechanochemical transformations in light of crystallographic characterization. It will highlight advancements in the crystallographic analysis of mechanochemical processes, including in situ monitoring and structural characterization of reaction intermediates and products. Key topics will include the role of crystal structure in determining reaction pathways, the development of new mechanochemical methodologies, and the applications of these techniques across disciplines ranging from materials science to pharmaceutical science.

MS098 Data quality and error analysis for diffuse scattering

Co-Chairs: Ella Schmidt & Graham King

SPONSORING COMMISSION: Crystallographic Computing

In experimental sciences, each observation is accompanied by a standard deviation or uncertainty, representing the reliability of the measurement. Experimental design aims to minimize these uncertainties. In diffraction experiments on crystals, a number of methods and algorithms are accepted for determining the uncertainties in the intensities of Bragg reflections. The analysis of diffuse scattering is more recent, and methods and algorithms still need to be established. This microsymposium will provide an opportunity to exchange ideas about experimental design and error analysis.

MS099 X-ray ptychography: recent developments and applications

Co-Chairs: Abraham Levitan & Ian Robinson

SPONSORING COMMISSION: Synchrotron and XFEL Radiation

X-ray ptychography is the highest-resolution X-ray microscopy technique available, capable of achieving spatial resolution below 5 nm under ideal conditions. It leverages the properties of coherent light to achieve resolution not limited by the numerical aperture of an optic but rather by the available coherent flux. Because of this, it is particularly well-suited for next-generation diffraction-limited storage rings, which promise dramatic increases in coherence. This microsymposium will highlight the latest advances in X-ray ptychography, including developments in instrumentation, data acquisition strategies, and reconstruction algorithms. Particular focus will be given to lessons learned from recent synchrotron upgrades at world-leading hard X-ray ptychography instruments and to the relevance of these improvements for a wide range of applications, from materials science and battery research to biological imaging and in situ studies.

MS100 Small molecule structure determination by electron diffraction

Co-Chairs: Daniel Decato & Johan Unge

SPONSORING COMMISSION: Electron Crystallography

CO-SPONSORING COMMISSION: Structural Chemistry

Electron diffraction is becoming a mainstream technique for solving structures that are intractable by conventional X-ray diffraction methods. The use of electron diffraction has enabled the determination of many small-molecule structures, including difficult targets such as MOFs and natural products, often directly from powder samples. This session will focus on applications of electron diffraction to the study of small molecules and novel structures. Novel approaches in sample preparation, analysis, or areas of application that enable these structures are also encouraged.

MS101 Protein-nucleic acid interactions in essential cellular functions

Co-Chairs: Markus Wahl & Cynthia Wolberger

SPONSORING COMMISSION: Biological Macromolecules

This session will cover fundamental cellular processes governed by interactions between proteins and nucleic acids, from chromatin remodeling to translation, including transcription regulation, splicing, and RNA processing.

MS102 Large scale structure determination initiatives revisited in the era of artificial intelligence and machine learning

Co-Chairs: Aled Edwards & Wladek Minor

SPONSORING COMMISSION: Biological Macromolecules

Large-scale NIH projects like Structural Genomics have had a significant impact over the past decade, shaping structural biology, drug discovery, and computational modeling. The legacy of SG includes databases, new computational tools, method standardization, and thousands of new structures that enabled the development of AI systems such as AlphaFold.

MS103 Crystal growth of quantum materials

Co-Chairs: Josie Auckett & Enrico Giannini

SPONSORING COMMISSION: Crystal Growth and Characterization of Materials

CO-SPONSORING COMMISSION: Quantum Crystallography

We invite contributions on crystal growth and characterization studies of a variety of quantum materials. Contributions will focus on recent developments in the growth and investigation of superconductors (novel and unconventional), low-dimensional materials, magnetic and multiferroic materials, Weyl semimetals, Dirac materials, and other topological materials.

MS104 New materials challenges addressed by cutting-edge small-angle x-ray and neutron instrumentation

Co-Chairs: Tyler B. Martin & Orion Shi

SPONSORING COMMISSION: Small Angle Scattering

CO-SPONSORING COMMISSION: Neutron Scattering

Small-angle X-ray and neutron scattering (SAXS/SANS) have developed into major techniques widely used in materials science, chemistry, and biology. Recent and upcoming upgrades at synchrotron and neutron sources, as well as advances in high-brightness home X-ray sources, provide opportunities for even greater advances in small-angle scattering instrumentation across a wide range of applications. This session will highlight new developments and capabilities in SAXS/SANS instrumentation from both large facilities and home sources, including hardware, software, and sample environments.

MS105 Magnetic order in complex materials: applications of resonant and non-resonant x-ray spectroscopy

Co-Chairs: Maria Angeles Laguna-Marco & Laurent Chapon

SPONSORING COMMISSION: XAFS

CO-SPONSORING COMMISSION: Magnetic Structures

SUPPORTING COMMISSION: Powder Diffraction

Though neutron scattering has long been the gold standard for probing the interplay between magnetic structure and physical properties in materials, modern synchrotron X-ray sources provide complementary methods for investigating magnetic systems. Synchrotrons offer exceptionally high flux and coherence, nanoscale spatial resolution, and unique spectroscopic capabilities involving resonant and non-resonant X-ray beams in either absorption or emission modes. Magnetic X-ray spectroscopies are especially useful in situations where neutrons face intrinsic limitations, such as thin films and interfaces, very small crystals, and materials with high neutron absorption rates. They can also be employed under extreme temperatures, pressures, and magnetic fields. Notably, X-ray magnetic circular dichroism (XMCD) and X-ray magnetic linear dichroism (XMLD) techniques probe the microscopic origins of exchange interactions and magnetic anisotropy and enable the separation of charge, orbital, and spin degrees of freedom. This session will highlight both methods and materials. We encourage contributions that showcase advancements in instrumentation, data analysis tools, and innovative X-ray scattering techniques (e.g., XMCD combined with resonant inelastic scattering of hard X-rays at the K-edge for a dichroic signal comparable to the L-edge), as well as applications of existing methods to new magnetic materials.

MS106 The use of three-dimensional pair-distribution functions to understand complex structures

Co-Chairs: Ray Osborn & Bo Iversen

SPONSORING COMMISSION: Aperiodic Crystals

This session will focus on the application of three-dimensional pair-distribution functions to better understand advanced materials and structural systems. Contributions that leverage cutting-edge diffraction methods, including multimodal approaches and time-resolved techniques, are strongly encouraged.

MS107 Coordination polymers and MOFs: rational design and functional control of periodic frameworks

Co-Chairs: Valentina Colombo & Jinhee Park

SPONSORING COMMISSION: Structural Chemistry

This microsymposium will focus on the rational design and controlled synthesis of coordination polymers and metal-organic frameworks (MOFs), exploring how periodic architectures can be tailored for specific functionalities. These materials have attracted broad interest due to their versatility in applications such as gas storage, catalysis, drug delivery, and sensing. The session will highlight innovative strategies for framework synthesis, structural characterization, and post-synthetic modifications, emphasizing the central role of crystallography in understanding and predicting material properties. Key topics include design principles for achieving target functionalities, the influence of metal-ligand coordination on stability, the development of novel building blocks, and controlled defect engineering to tune material properties.

MS108 In vivo crystallography and synchrotron radiation

Co-Chairs: Leonard Chavas & Gema Martinez Criado

SPONSORING COMMISSION: Synchrotron and XFEL Radiation

In vivo crystallography is emerging as a powerful method for studying protein structures in their native cellular environments, offering new insights into biomolecular function and interactions. Unlike traditional in vitro approaches, in vivo-grown crystals can provide structural information under physiological conditions, capturing transient states and biologically relevant conformations. When combined with synchrotron radiation, this technique enables high-resolution diffraction studies without extensive sample manipulation. With the continuous evolution of synchrotron sources, including fourth-generation storage rings and microfocused beamlines, in vivo crystallography is becoming increasingly feasible. Advances in diffraction data collection, sample preparation, and in situ analysis have opened new frontiers for structure determination of challenging targets, including membrane proteins, large macromolecular complexes, and proteins that are difficult to crystallize in vitro. This session will highlight the latest developments in in vivo crystallization, data acquisition strategies, and the role of synchrotron facilities in supporting these studies.

MS109 Nanocrystallography of natural and synthetic inorganic compounds

Co-Chairs: Philippe Boullay & Stephanie Kodjikian

SPONSORING COMMISSION: Electron Crystallography

Many interesting compounds, both natural and synthetic, are crystallized in nanocrystalline form. While the first crystallization of nanomaterials involved simple crystal structures, more complex nanomaterials are now driving the need for improved ad hoc structure solution methods. This session is devoted to the recent development of electron and X-ray diffraction techniques that are applied to the structure determination of new inorganic compounds that may otherwise be challenging due to small crystal and/or crystalline domain sizes. Crystallographic tools able to elucidate the crystal structure of nanomaterials are mandatory for modern materials science. This session will be a bridge between novel synthesis approaches, such as mechanochemistry, and advanced X-ray and electron diffraction nanobeam techniques which can provide crystal structures from nanocrystalline powder, supported thin films, or a nanocrystalline domain inside a matrix. Additionally, these same techniques, applied to mineralogy, will shed new light on the petrology of extreme conditions and rare nanominerals.

MS110 Hydrogen-bearing compounds at extreme conditions

Co-Chairs: Vitali Prakapenka & Xiancheng Wang

SPONSORING COMMISSION: High Pressure

CO-SPONSORING COMMISSION: Crystallography of Materials

Hydrogen-bearing compounds have attracted extensive attention due to their distinctive physical and chemical properties under extreme pressures and temperatures, leading to the formation of new compounds or metastable phases with unique characteristics relevant to hydrogen storage technologies, room-temperature superconductors, and hydrogen-rich minerals and ices in planetary interiors. This microsymposium will focus on interdisciplinary research advancing the technology, characterization, and application of hydrogen-bearing materials synthesized at high-pressure and high-temperature conditions. Theoretical contributions will cover cutting-edge predictions using computational modeling to design novel phases with diverse hydrogen bonding and structures. Experimental presentations will address high-pressure synthesis techniques and innovative approaches for stabilizing hydrogen phases, including super-hydrates. The session will also highlight advanced in situ characterization of structural and physical properties using state-of-the-art techniques available in laboratories and large facilities, including electrical transport measurements, magnetic susceptibility analysis, and elastic and structural determination with X-ray and optical methods. This microsymposium aims to foster collaboration between theoretical and experimental groups to accelerate breakthroughs in hydrogen-bearing materials research.

MS111 Structural biology of receptors and transporters

Co-Chairs: Hideaki Kato & Giovanna Scapin

SPONSORING COMMISSION: Biological Macromolecules

Membrane proteins play a crucial role in cell physiology, acting as receptors and transporters of solutes. A significant number of small-molecule drugs target human membrane proteins, including the most extensively studied group, G protein-coupled receptors, as well as ion channels and metabolite transporters. This session will explore the structure-function relationships of these key classes of membrane proteins.

MS112 Crystal and magnetic structures of novel perovskites and perovskite-related materials

Co-Chairs: Brendan Kennedy & Patrick Woodward

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Powder Diffraction

SUPPORTING COMMISSION: Inorganic and Mineral Structures

The broader perovskite structure family combines a simple crystal motif with a great diversity of cation compositions and framework dimensions, which drive a remarkable variety of physical properties. This session will focus on electronic, magnetic, and optical structure-property relationships and applications in novel perovskite and perovskite-related materials of both the inorganic and hybrid organic-inorganic varieties, and may also touch on other important material classes.

MS113 Sustainable energy materials for the future: local structure

Co-Chairs: James K Harper & Veronica Celorrio Remartinez

SPONSORING COMMISSION: NMR Crystallography and Related Methods

CO-SPONSORING COMMISSION: XAFS

This microsymposium will highlight advanced characterization techniques used to elucidate the local structure and dynamics of a wide range of sustainable and energy materials, including energy storage and conversion systems (e.g., metal-air batteries and fuel cells), MOFs, ion-conducting oxides, zeolites, layered double hydroxides, and complex oxide phases. Understanding local structure and dynamics is essential for linking material properties to their functional behavior. The session will focus on the application of NMR crystallography and X-ray absorption spectroscopy (XAS) to obtain element-specific information about the local and electronic structure of these materials across different length and time scales. Particular emphasis will be placed on the potential synergies between NMR and XAS in providing deeper insight into the functional properties of complex systems. The complementarity of these approaches, together with their applicability to real-life conditions, makes NMR and XAS powerful tools for probing reaction processes in sustainable materials. The in-depth understanding gained through these studies is significant for guiding the design of new materials and advancing more efficient and sustainable energy solutions. This microsymposium will form part of a two-part series dedicated to sustainable materials.

MS114 Quantum crystallography: applications to biological systems

Co-Chairs: Parthapratim Munshi & Ulf Ryde

SPONSORING COMMISSION: Quantum Crystallography

CO-SPONSORING COMMISSION: Biological Macromolecules

Quantum crystallography plays an important role in advancing the understanding of biological systems because it explores molecular structure and interactions at the atomic level through the effects of electron distribution. Better characterization and modeling of electron density in biological molecules offer deeper insights into biomolecular bonding and reaction mechanisms. This is particularly relevant to understanding enzyme catalysis, protein-ligand interactions, and the structural basis of diseases. Drug design can be enhanced by accurately modeling how pharmaceuticals interact with biological targets, leading to improved efficacy and reduced side effects. Moreover, quantum crystallography provides insight into the role of weak interactions, such as hydrogen bonding and van der Waals forces, in stabilizing complex biological structures. Quantum crystallography is indispensable in the study of biological systems because deeper insights require the increased level of detail that quantum crystallography provides.

MS115 X-ray spectroscopy, neutron and muon methods in art and archaeology

Co-Chairs: Solenn Reguer & Antonella Scherillo

SPONSORING COMMISSION: XAFS

CO-SPONSORING COMMISSION: Crystallography in Art and Cultural Heritage

X-ray spectroscopy, neutron, and muon techniques are widely used for the study and conservation of artistic, historical, and archaeological materials and artifacts. The chemical selectivity of X-ray absorption spectroscopy (XAS), combined with its high sensitivity, makes it an ideal tool for investigating complex and heterogeneous materials. Its ability to perform chemical mapping with high spatial resolution is particularly valuable, as it provides information about local composition and chemical states of selected elements in a sample. Muon- and neutron-based methods such as imaging and bulk elemental analysis are also well-established research tools in cultural heritage, as they reveal the internal composition, structure, and microstructure of objects that may otherwise be hidden from view and inaccessible to other analytical probes. The aim of this microsymposium is to demonstrate the applicability of XAS, muon, and neutron methods for studying historically and archaeologically valuable artifacts, illuminating aspects of their fabrication and methods for conserving them for future generations.

MS116 Teaching crystallographic computing

Co-Chairs: Larry Falvello & Kathryn Cowtan

SPONSORING COMMISSION: Crystallographic Computing

Most students learn programming as part of their curriculum. Nevertheless, the application of this knowledge to crystallographic purposes is limited. The aim of this microsymposium is to present courses, seminars, and tools for crystallographic computing education. These efforts can range from small ad hoc routines to larger projects. The use of crystallographic, general scientific, statistical, and graphical libraries for teaching is encouraged. Teaching websites may be presented, as well as examples of setting up appropriate computing infrastructures.

MS117 From interactions to functions: use of hydrogen bond, halogen bonds, and a toolbox of interactions to drive the design of materials

Co-Chairs: Susan Bourne & Giancarlo Terraneo

SPONSORING COMMISSION: Structural Chemistry

This microsymposium will explore the critical role of non-covalent interactions in the rational design of functional materials. By leveraging a diverse toolbox of interactions, researchers can tailor material properties for a wide range of applications, from pharmaceuticals to advanced materials. The session will highlight cutting-edge research on the characterization and manipulation of these interactions using crystallographic techniques. Key topics will include the principles governing the formation and strength of hydrogen bonds, halogen bonds, and the full spectrum of weaker interactions; the synergistic effects of multiple interactions; and case studies demonstrating the successful design of materials with desired functionalities. By carefully controlling intermolecular forces like hydrogen bonding, halogen bonding, and other non-covalent interactions, we can create materials with specific properties such as desired melting points, solubility, viscosity, and mechanical strength. This is realized by adjusting the molecular structure to encourage or block certain interactions. However, designing these materials comes with challenges, such as the simultaneous operation of multiple types of intermolecular interactions and the significant effects of external factors such as temperature and solvent. With the field of crystal engineering advancing rapidly, it is timely to host a microsymposium on the wide range of interactions that can be used to design innovative materials.

MS118 Inclusion and belonging in structural science

Co-Chairs: Cristy Nonato & Bernie Santarsiero

SPONSORING COMMISSION: IUCr Early Career Scientist Division

This microsymposium brings together contributions from experts who have been addressing issues of diversity, equity, and inclusion, and examining how scientific organizations can foster more inclusive and fair spaces. It explores how these environments promote a sense of belonging, increase the relevance of our Union, and are perceived across different stages of scientific life, with particular attention to younger generations of structural scientists. The session also reviews the progress achieved so far, highlights the challenges that remain, and discusses strategies to build a more inclusive and broader community.

MS119 X-ray and electron crystallography: from single crystal to serial diffraction

Co-Chairs: Sarah Bowman & Xiaodong Zou

SPONSORING COMMISSION: Electron Crystallography

CO-SPONSORING COMMISSION: Synchrotron and XFEL Radiation

SUPPORTING COMMISSION: Structural Chemistry

X-ray and electron crystallography are powerful techniques for determining the atomic structures of a wide range of materials, from biological macromolecules to complex inorganic and organic compounds. While X-ray crystallography remains a primary method for high-resolution structure determination, electron crystallography is emerging as a complementary technique, particularly for submicron-sized crystals and challenging samples that are difficult to study using traditional methods. This microsymposium will explore the latest advancements in both techniques, including hybrid and serial approaches that leverage their respective strengths. Topics will include advances in sample preparation, data collection, processing algorithms, serial diffraction, and applications in structural biology, materials science, and chemistry.

MS120 Extreme conditions unveiled: the synergy of computational models and experimental techniques

Co-Chairs: TBD & Ricardo Donizeth dos Reis

SPONSORING COMMISSION: High Pressure

This microsymposium will focus on the combined use of computational modeling and experimental methods to study materials under extreme conditions. Emphasis will be placed on advanced techniques, including grazing-incidence methods, reciprocal space mapping, and reflectometry, which reveal interfacial phenomena and nanoscale structure-property relationships. Contributions highlighting the integration of simulations with experimental data to achieve deeper insights into material behavior are strongly encouraged.

MS121 Tribute to George Sheldrick: legacy of a crystallographic computing pioneer

Co-Chairs: Regine Herbst-Irmer & Isabel Uson

SPONSORING COMMISSION: Biological Macromolecules

CO-SPONSORING COMMISSION: Crystallographic Computing

SUPPORTING COMMISSION: Structural Chemistry

George Sheldrick's contributions to crystallographic computing have left an indelible mark on the field. Sheldrick's innovations have been instrumental in advancing structural science through the development of SHELX, a suite of programs that revolutionized chemical structure determination and was extended to applications in mineralogy, with the flexibility to handle twinning and disorder, and in biology, notably experimental phasing and refinement. This special session will celebrate his legacy, featuring talks on the impact of his algorithms, the evolution of structure refinement, and the influence of SHELX in modern crystallographic workflows. Colleagues and researchers who have built upon his work will discuss past achievements, ongoing developments, and future directions inspired by his contributions.

MS122 Structural chirality and spin properties of chiral matter

Co-Chairs: Roger Johnson & Vladimir Pomjakushin

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Crystallography of Materials

Chirality is a fundamental symmetry concept that plays a crucial role in materials science and condensed matter physics. It can be defined for both crystal and magnetic subsystems, and the interplay between them is also an exciting topic. Magnetic interactions activated in chiral crystals often promote exotic ground states, such as long-period modulated magnetic structures, skyrmion lattices, and soliton lattices. This microsymposium will focus on spin ordering in chiral crystals and will include discussion of symmetry principles and microscopic mechanisms underlying the interplay between structural and magnetic chirality.

MS123 Defects in semiconductor crystals: how they influence device performance

Co-Chairs: Mike Leszczynski & Ewa Grzanka

Invited Speakers: Mark Goorsky, Lutz Kirste & Marta Sobanska

SPONSORING COMMISSION: Crystal Growth and Characterization of Materials

Semiconductor substrates and epitaxial structures are among the most important crystals in our modern world. Most of them have relatively simple crystallographic structures, such as zinc blende, wurtzite, or rocksalt. However, they still exhibit a variety of extended and point defects, which strongly influence the performance of transistors, diodes, and lasers. This microsymposium aims to provide an opportunity for exchanging information on how these defects can be detected and how they influence the properties of semiconductor devices.

MS124 Applications of machine learning and artificial intelligence in biological small angle scattering

Co-Chairs: Michal Hammel & Xiaobing Zuo

SPONSORING COMMISSION: Small Angle Scattering

Biological small-angle scattering (SAS), including small-angle X-ray scattering (SAXS) and small-angle neutron scattering (SANS), is a powerful technique for probing biomolecular structures in near-physiological conditions. Over the past decades, advances in high-throughput instrumentation and data analysis methods have significantly enhanced the speed and accessibility of SAS. However, SAS data remain inherently low resolution, often leading to ambiguity in structural analysis. Additionally, many BioSAS modeling approaches are computationally intensive, lagging behind the rapid pace of data collection. To address these challenges, machine learning (ML) and artificial intelligence (AI) are emerging as transformative tools, enabling more efficient, accurate, and high-throughput SAS data analysis. This microsymposium will highlight cutting-edge ML and AI applications in biological SAS, including AI-driven automated data processing, feature extraction, model selection, and structural reconstruction. Additionally, the session will explore the integration of SAS data with complementary structural techniques, advanced modeling approaches, and atomic structure predictions. By leveraging ML and AI, researchers can enhance experimental efficiency, streamline data interpretation, and extract more precise structural insights, ultimately expanding the capabilities of SAS-based biomolecular studies.

MS125 Accurate molecular structure determination from X-ray, neutron and electron diffraction

Co-Chairs: Arianna Lanza & Stefano Canossa

SPONSORING COMMISSION: Crystallographic Teaching

The increasing throughput of diffraction experiments, supported by the growing automation of software for data processing, is fueling a surge in the number of structures published every year. At the same time, the development and wider distribution of advanced methods (e.g., non-spherical scattering factors or dynamical refinement) enable us to produce more detailed and complex structural models. With these powerful tools come great responsibilities for the crystallographers of today and tomorrow: to critically assess the quality of results and make the most of experimental datasets while avoiding overinterpretation or incorrect use of the data. By showcasing complicated case studies and appropriate methodologies, this microsymposium aims to propose useful practices for upholding the accuracy of structural models, especially in cases where limited data quality or high model complexity require thoughtful validation of the results.

MS126 From dynamic to self-healing molecular crystals

Co-Chairs: Sajesh Thomas & Delia Haynes

SPONSORING COMMISSION: Structural Chemistry

The microsymposium is focused on structure-property relationships in dynamic molecular crystals with properties such as mechanical flexibility, towards potential applications as piezoelectrics, ferroelectrics, and piezoresistive materials, amongst others. Recent computational and experimental advancements in the understanding of intermolecular dynamics in mechanically flexible molecular crystals may offer insights into the development of crystal engineering approaches in this direction.

MS127 Crystallography and spectroscopy in sustainable resource management

Co-Chairs: Chris Cahill & Aram Bugaev

SPONSORING COMMISSION: Inorganic and Mineral Structures

CO-SPONSORING COMMISSION: XAFS

This microsymposium will explore the role of crystallography in understanding, optimizing, and innovating the use of critical elements essential for modern technologies. Topics will include the structural characterization of critical raw materials, advances in crystallographic techniques for resource efficiency, and the development of new materials for green technologies. By exploring element substitution, recycling strategies, and the design of novel functional materials, this microsymposium aims to highlight how crystallography can contribute to reducing dependence on scarce or geopolitically sensitive elements while promoting sustainable development.

MS128 Data-driven science: current status and outlook

Co-Chairs: Dritan Siliqi & Cy Jeffries

SPONSORING COMMISSION: Synchrotron and XFEL Radiation

SUPPORTING COMMISSION: CommDat

The exponential growth of data produced at synchrotron and XFEL facilities has positioned data-driven science at the forefront of discovery. Increasingly, advanced machine learning (ML) and artificial intelligence (AI) methods are being embedded directly into experimental workflows, enabling real-time analysis, automated decision-making, and predictive modeling. This session will present cutting-edge developments in data-driven approaches for X-ray and neutron science, with a focus on innovations in data acquisition, processing, and analysis. Particular attention will be given to emerging algorithms, cloud-enabled platforms, and the adoption of FAIR data principles to ensure interoperability and reusability across facilities. Speakers will also address key challenges, including managing large-scale datasets and broadening accessibility of AI/ML tools for diverse scientific communities. Finally, the role of AI in optimizing beamline operations and guiding experimental design will be explored, highlighting its potential to transform the future of photon and neutron science.

MS129 How mathematics opens minds and black boxes in crystallography

Co-Chairs: Angela Altomare & Gemma de la Flor Martin

SPONSORING COMMISSION: Mathematical and Theoretical Crystallography

CO-SPONSORING COMMISSION: Magnetic Structures

Mathematical concepts such as group theory, symmetry, Fourier transforms, and geometric transformations are fundamental to crystallography. While tools and software based on these concepts are indispensable in the field, relying on these “black boxes” without a basic understanding of the underlying theory can lead to errors or misinterpretations. Results produced by such programs should not be trusted blindly; instead, they must be evaluated in light of the mathematical principles behind them. Based on examples from everyday crystallographic practice, this microsymposium will explore how these core mathematical concepts are crucial for solving crystallographic problems and how they can help identify potentially misleading results that may arise from crystallographic software.

MS130 Artificial intelligence and machine learning in crystallography and scattering

Co-Chairs: Anders Madsen & Thomas Proffen

SPONSORING COMMISSION: Crystallographic Computing

CO-SPONSORING COMMISSION: Synchrotron and XFEL Radiation

SUPPORTING COMMISSION: Small Angle Scattering

Artificial intelligence (AI) and machine learning (ML) are rapidly transforming the landscape of crystallography and scattering techniques, offering groundbreaking tools for data analysis, structure prediction, and experimental automation. As the volume and complexity of crystallographic and scattering data continue to grow, ML algorithms provide powerful methods for pattern recognition, crystal structure classification, and optimization of experimental parameters. Applications include automated phase determination, enhancement of electron density map interpretation, prediction of crystal packing, and identification of new materials with tailored properties. Deep learning techniques, such as convolutional neural networks (CNNs), have shown particular promise in image-based tasks like crystal identification and segmentation, while reinforcement learning is being explored for optimizing experimental workflows. At synchrotron and XFEL facilities, AI-driven approaches are accelerating data processing, enabling autonomous experiments, and enhancing structure refinement processes. This microsymposium will highlight recent advances in the integration of AI and ML across crystallography and scattering, with contributions from researchers developing and applying these tools to X-ray and neutron scattering, single-particle imaging, and materials characterization. It will also address current challenges in model interpretability, data curation, and software integration. The synergy between AI and traditional methodologies is poised to revolutionize the field by enabling faster, more accurate, and more reproducible analyses.

MS131 Tribute to George Sheldrick: legacy of a crystallographic computing pioneer

Co-Chairs: Regine Herbst-Irmer & Isabel Uson

SPONSORING COMMISSION: Biological Macromolecules

CO-SPONSORING COMMISSION: Crystallographic Computing

SUPPORTING COMMISSION: Structural Chemistry

George Sheldrick's contributions to crystallographic computing have left an indelible mark on the field. Sheldrick's innovations have been instrumental in advancing structural science through the development of SHELX, a suite of programs that revolutionized chemical structure determination and was extended to applications in mineralogy, with the flexibility to handle twinning and disorder, and in biology, notably experimental phasing and refinement. This special session will celebrate his legacy, featuring talks on the impact of his algorithms, the evolution of structure refinement, and the influence of SHELX in modern crystallographic workflows. Colleagues and researchers who have built upon his work will discuss past achievements, ongoing developments, and future directions inspired by his contributions.

MS132 Pharmaceutical materials

Co-Chairs: Rajni Miglani Bhardwaj & TBD

SPONSORING COMMISSION: Structural Chemistry

Pharmaceutical molecules can exist in multiple solid-state forms, such as polymorphs, hydrates, salts, and co-crystals. These solid-state forms may exhibit different physical, chemical, kinetic, surface, and mechanical properties, which can lead to differences in bioavailability, manufacturability, and stability of drug products. This microsymposium will focus on correlating structure-property-performance relationships in developing more effective drug products and on how combined experimental and computational approaches can provide a deeper understanding of these relationships.

MS133 Advancing exotic magnetism in two-dimensional and layered materials

Co-Chairs: Young-June Kim & Ovidiu Garlea

SPONSORING COMMISSION: Magnetic Structures

CO-SPONSORING COMMISSION: Quantum Crystallography

SUPPORTING COMMISSION: Crystal Growth and Characterization of Materials

Two-dimensional (2D) magnetic materials provide an exciting platform for discovering novel quantum phases, spin interactions, and exotic excitations. From triangular and honeycomb lattice systems to van der Waals (vdW) magnets, these materials offer new opportunities to study fundamental magnetic phenomena and their potential applications in spintronics and quantum technologies. In particular, the realization of Kitaev interactions in 2D systems has opened pathways to uncovering quantum spin liquids and other emergent states driven by strong spin-orbit coupling and competing interactions. This microsymposium invites contributions on the synthesis, characterization, and theoretical modeling of 2D magnetic materials, including vdW magnets, Kitaev candidates, and other low-dimensional quantum systems. By bringing together researchers across different disciplines, this microsymposium aims to advance our understanding of low-dimensional magnetism and its role in next-generation quantum materials.

MS134 Crystallography and x-ray absorption spectroscopy machine learning methods for the development of materials

Co-Chairs: Kamil Dziubek & Adam Clark

SPONSORING COMMISSION: CommDat

CO-SPONSORING COMMISSION: XAFS

SUPPORTING COMMISSION: Crystallography of Materials

The role of artificial intelligence (AI) and machine learning (ML) methods in the development of materials is hard to overestimate. Applying deep learning to materials genomics accelerates the discovery and design of new functional materials. Moreover, ML-assisted structural data mining accelerates structure prediction and facilitates the study of structure-property relationships based on experimental data. This approach can be extended to exploring phase transitions and constructing phase diagrams in pressure-temperature-composition space. Notably, ML is also employed in materials science to interpret experimental data by combining information from multiple diagnostics, including single-crystal and powder diffraction, pair distribution function analysis, XANES, and EXAFS. Finally, the scope of this microsymposium will encompass the contribution of AI to the foundations of crystallographic methods, such as ML-enhanced solutions to the phase problem. This microsymposium will cover the most critical aspects of how the advent of AI has changed the paradigm of in silico materials development and will discuss future prospects.

MS135 Multiscale diffraction-based x-ray and neutron imaging

Co-Chairs: Axel Henningson & Henning Poulsen

SPONSORING COMMISSION: Diffraction Microstructure Imaging

CO-SPONSORING COMMISSION: Neutron Scattering

Over the past two decades, a suite of diffraction-based x-ray imaging methods for 3D mapping of microstructure and local stress, strain, and orientation in crystalline materials has matured. At synchrotron facilities, these methods include 3DXRD/HEDM, DCT, scanning-3DXRD, DFXM, DAXM, Bragg CDI, and Bragg ptychography. Beyond synchrotrons, researchers also benefit from neutron facilities, XFEL instruments, and laboratory x-ray sources. Together, these complementary methods provide comprehensive coverage, with fields of view from 1 µm to 10 cm, spatial resolutions from 10 µm down to 15 nm, and time scales from hours to picoseconds..

Motivated by this multiscale coverage, the micro-symposium focuses on advances in theory, instrumentation, data analysis, forward simulation tools, and interfaces to materials or mechanical modelling that expand possibilities for multiscale and multimodal studies. Topics include coupling length and time scales, both experimentally and through regularisation and statistical analysis, and adding contrast by combining methods at the same length and time scales. We welcome work on new methodologies, science cases, and cross-disciplinary electron (EBSD) and x-ray microscopy efforts that illuminate multiscale synergies across experimental methods and modelling.

MS136 Multi-stimuli responsive molecular crystals

Co-Chairs: Florencia Di Salvo & Dr. Manas Panda

SPONSORING COMMISSION: Structural Chemistry

This microsymposium will cover recent developments in soft molecular crystals that respond to multiple external stimuli. Developing a single material capable of responding to multiple stimuli is a challenging task. Such materials represent an important class for various technological applications where multitasking is required.

MS137 Software for crystal growth and form

Co-Chairs: Andrea Erxleben & Mike Probert

SPONSORING COMMISSION: Crystallographic Computing

Crystal morphology is very important for the efficiency and formulation of solid pharmaceuticals and plays a key role in the properties of organic and inorganic materials. It is also essential for the fundamental understanding of crystals in the bulk and on surfaces. Relating the internal structure of crystals with their external morphology began with Bravais (1811-1863), who relied purely on unit cell parameters and space group symmetry. In the 20th century, this geometrical approach was refined, and the importance of energy also became clear. More recently, many new algorithms have appeared that revolutionized predictive possibilities. This microsymposium offers a platform to present new software and new understanding of the basis of crystal growth and form.

MS138 Room-temperature serial snapshot micro-crystallography: highlights from xfels and synchrotrons

Co-Chairs: José Manuel Martín-García & Swagatha Ghosh

SPONSORING COMMISSION: Synchrotron and XFEL Radiation

Serial snapshot microcrystallography at room temperature is transforming structural biology by revealing biomolecular structures and dynamics under conditions that closely mimic the native state. This microsymposium will highlight the latest breakthroughs at both XFELs and next-generation synchrotron sources. Speakers will present cutting-edge developments in sample delivery (including fixed targets, liquid jets, and emerging hybrid methods), real-time and time-resolved data acquisition, and advanced analysis pipelines that extract maximum information from massive serial datasets. Case studies will showcase how these approaches uncover hidden conformational ensembles, capture short-lived reaction intermediates, and bridge the capabilities of synchrotrons and XFELs to deliver complementary insights. By bringing together pioneers from both facility types, this microsymposium will foster cross-disciplinary discussion on how room-temperature serial crystallography is reshaping our understanding of macromolecular structure, dynamics, and function.

MS139 Current challenges and new strategies for the IUCr journals

Co-Chairs: Andrew Allen & Kristina Kvashnina

SPONSORING COMMISSION: IUCr Early Career Scientist Division

For over 75 years, the International Union of Crystallography (IUCr) has been at the forefront of scholarly publishing in the structural sciences. This microsymposium will examine how IUCr’s journals, International Tables, and books have influenced global standards of quality, transparency, and reproducibility. Presentations will explore IUCr’s continuing leadership in open-access policy, data archiving, integration of AI tools, and sustainable publishing models for scientific societies. The session will focus on how IUCr can continue to serve authors, reviewers, and readers while maintaining scientific integrity and accessibility for a worldwide community. Historical perspectives will illustrate IUCr’s role in setting norms for data and peer review, and forward-looking discussions will consider how IUCr can adapt these traditions to new technologies and expectations.

MS140 Electron crystallography for biological macromolecules

Co-Chairs: Max Clabbers & Gerhard Hofer

SPONSORING COMMISSION: Electron Crystallography

CO-SPONSORING COMMISSION: Biological Macromolecules

Obtaining sufficiently sized and ordered crystals remains a major challenge in macromolecular crystallography, particularly for membrane proteins. Electron diffraction operates at the interface of crystallography and electron microscopy and enables structure determination from crystals that are far too small for conventional crystallographic methods. This microsymposium will highlight recent advances in macromolecular electron crystallography, including microcrystal electron diffraction (MicroED) and serial electron diffraction (SerialED). Presentations will showcase novel biological applications alongside methodological developments in sample preparation, data collection, and refinement strategies for electron diffraction data.

MS0 Career exploration panel

Co-Chairs: Raphael de Wijn & David Dranow

SPONSORING COMMISSION: IUCr Early Career Scientist Division

Join us for an engaging discussion as scientists with various careers across academia and industry share their personal journeys, challenges, and triumphs in the field. What makes each career path fulfilling? What are different academic and industrial career paths? What key decisions shape professional growth and satisfaction? This session offers valuable insights for scientists at all stages, with a special focus on guidance for early-career professionals. Gain practical advice, explore diverse career paths, and learn what it takes to build a rewarding and impactful career.

MS0 Open problem session

Co-Chairs: Alex Dommann & Gregory McColm

SPONSORING COMMISSION: Mathematical and Theoretical Crystallography

Open problem sessions are common at mathematics and medicine conferences. This session will follow a standard format: it will be presided over by a moderator and possibly a stenographer, who will serve as co-chairs. The primary support material will be a full-sized newsprint pad on an easel. The organizers may begin with a brief enumeration of outstanding open problems in the community. Audience members will then be invited to comment on these problems, with both the problems and comments recorded on the pad in writing large enough for participants to photograph with their phones. After this prologue, the moderator will invite the audience to present additional open problems and comments, which will also be recorded. The session is expected to last about two hours. Following the session, the problems and comments will be transcribed, and members of the audience who sign up will receive copies of the transcription.