Schedule

Structural Chemistry
Keynote

Crystallography of Materials
Keynote

Biological Macromolecules
Keynote

Co-Chairs: Albert Berghuis & Anne Jecrois 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 over the past few 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 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.

Biological Macromolecules

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.

Biological Macromolecules

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.

Crystallography of Materials
Magnetic Structures

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.

NMR Crystallography and Related Methods
Structural Chemistry

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.

Small-Angle Scattering

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.

Aperiodic Crystals
Mathematical and Theoretical Crystallography

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.

Powder Diffraction
XAFS

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.

Diffraction Microstructure Imaging
Neutron Scattering
Powder Diffraction

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.

Structural Chemistry

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.

Biological Macromolecules
Crystallographic Computing

Organizers: Santosh Panjikar & Martin Lutz The Software Fayre at the 27th IUCr Congress (Calgary, August 11-18, 2026) offers a forum for developers to present new crystallographic software and demonstrate their features through hands-on tutorials. The Fayre will be held August 12-18, with time slots available for registration.

Crystallographic Computing

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.

Biological Macromolecules

Co-Chairs: Elizabeth R. Wright & Stefan Raunser 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.

Biological Macromolecules

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.

Crystallographic Computing
Magnetic Structures
Powder Diffraction

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.

Crystallography of Materials
Magnetic Structures
Powder Diffraction

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.

Small-Angle Scattering

Co-Chairs: Kenji Tsuda & Paulina Dominiak 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.

Electron Crystallography
NMR Crystallography and Related Methods
Quantum Crystallography

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.

Powder Diffraction
XAFS

Co-Chairs: Aaron Brewster & Christine Beavers Sponsoring Commission: CommDat Co-Sponsoring Commission: Electron Crystallography Data collection volume and velocity have increased dramatically in the past 5-10 years. High-throughput, serial, and electron crystallography are examples of techniques that not only produce large volumes of data and results rapidly but also challenge traditional notions of quality and definitive outcomes. These challenges with data processing and analysis relate both to “keeping up” and to generating the best possible quality results and determining their suitability for specific applications. Knock-on consequences also arise for data reuse and data-driven science, with potential impacts on database population, variability in results, and questions of suitability for follow-on work such as training AI models. Driven by practical examples and evolving best practices, this general-interest microsymposium will address the current data challenges, ranging from raw data processing through refinement, quality assessment, raw data archiving and reuse, to validity in data science.

Electron Crystallography
CommDat

Co-Chairs: Daumantas Matulis & Anuradha Pallipurath Sponsoring Commission: Structural Chemistry 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.

Structural Chemistry
CommDat

Co-Chairs: Matthew Gyton 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.

Structural Chemistry

Biological Macromolecules
Plenary