Schedule

Crystal Growth and Characterization of Materials
Keynote

Keynote

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.

Biological Macromolecules
Crystallographic Computing
Structural Chemistry

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.

Crystal Growth and Characterization of Materials
Magnetic Structures

Co-Chairs: Mike Leszczynski & Ewa Grzanka 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.

Crystal Growth and Characterization of Materials

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.

Small-Angle Scattering

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.

Crystallographic Teaching

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.

Structural Chemistry

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.

Inorganic and Mineral Structures
XAFS

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.

Synchrotron and XFEL Radiation
CommDat

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.

Magnetic Structures
Mathematical and Theoretical Crystallography

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.

Crystallographic Computing
Small-Angle Scattering
Synchrotron and XFEL Radiation

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: 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.

Biological Macromolecules
Crystallographic Computing
Structural Chemistry

Co-Chairs: Rajni Miglani Bhardwaj 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.

Structural Chemistry

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.

Crystal Growth and Characterization of Materials
Magnetic Structures
Small-Angle Scattering

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.

Crystallography of Materials
XAFS
CommDat

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, this microsymposium will focus on advances in theory, instrumentation, data analysis, forward simulation tools, and interfaces to materials or mechanical modeling that expand possibilities for multiscale and multimodal studies. Topics include coupling length and time scales, both experimentally and through regularization and statistical analysis, as well as adding contrast by combining methods at the same length and time scales. Contributions are welcome on new methodologies, science cases, and cross-disciplinary electron (EBSD) and X-ray microscopy efforts that illuminate multiscale synergies across experimental methods and modeling.

Diffraction Microstructure Imaging
Neutron Scattering

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.

Structural Chemistry

Co-Chairs: 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.

Crystallographic Computing

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.

Synchrotron and XFEL Radiation

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.

IUCr Early Career Scientist Division

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.

Biological Macromolecules
Electron Crystallography