Microsymposiums

This microsymposium with focus on new developments in the field of (inorganic) pigment degradation, and on the relation between X-ray diffraction as a structural, quantitative and highly specific means of identifying primary and secondary pigments and related materials inside slowly degrading works of art. Attention will also be given to how insights obtained through (X-ray) analysis makes art conservation more effective and more sustainable.

Pigmented artists' materials often are semi-conducting crystalline solids containing a heavy metal ion (e.g. Cr or Pb) linked to either to an oxyanion (e.g. sulphate, chromate, ...) or to a inorganic (e.g,, sulphide, fluoride, chloride, ...) or organic ligand (e.g., carbonate, formate, acetate, ...). These compounds are prone to photo-induced or thermally induced redox reactions where either the metal ion or its counter ion or both is subject to a reduction or oxidation. The result may be a partial loss of crystallinity of the original compound and the formation of one or more secondary compounds of crystalline nature. Such spontaneous transformations can take place during periods of several 100 to 1000th of years, depending on the age of the work of art and its environmental circumstances (light, temperature, chemical agents in the vicinity, moisture, ...).

To study these transformations for the benefit of rendering art conservation practice more fit-for-purpose and to slow down or prevent these processes, art objects can be either analysed non-invasively using X-ray powder diffraction (spot analyses but increasingly also via mapping methods) or via more detailed analysis of small material samples, removed from the artworks. Since the paint microsamples taken from works of art typically are multilayered and consist of several strata of different paint, typicall a few to 10s of micrometers in thickness, such samples are typically examined using synchrotron methods. In many cases, a combination of microscopic X-ray fluorescence (μ-XRF), X-ray absorption spectroscopy (μ-XANES) and X-ray powder diffraction (μ-XRPD) in mapping mode (2D) or via line-tomography (3D) is employed. In some cases, also more recent SR based methods such as phychography are being used to characterize paint micro-samples.

Session Chair: Prof Koen Janssens

This microsymposium will focus on the role crystallography plays in the study of materials employed by artists in various historical periods to create cultural heritage artefacts. These materials can be quite diverse ranging from a variety of minerals (e.g. used as pigments), various type of rocks and wood (e.g., used as substrate or to carve intricate shape into), metals (iron, bronze, tin, gold, ... and their alloys) as well as various materials of animal or plant origin (e.g. bone, antler, fibres, ...). To study the manufacturing technology of cultural heritage artefacts of various kinds (e.g. armour, furniture, paintings, drawings, ceramics, ...) the identification of the crystalline compounds present in the bulk and at the surface of ancient cultural heritage artefacts is usually of paramount importance. In many cases, XRD is only one of the methods employed to analyzes the materials in a non-invasive manner next to various other structural methods (e.g. NMR, Raman, FTIR, ...).

Session Chairs: Dr Silvie Svarcova and Dr Catherine Dejoie

This microsymposium aims at collecting presentations on recent developments in the crystallography of incommensurate modulated and incommensurate composite crystals. The focus is on contributions that may provide a link between synthesis, incommensurate crystal structure, crystal chemistry of the investigated compounds, and physical properties of these materials.

Session Chairs: Dr Anna Gagor and Dr Ella Schmidt

Quasicrystals are a form of matter that is ordered but not periodic. They are found in bulk alloys, as thin films, and in various forms of soft matter. Recent research elucidated the crystallographic structure of quasicrystals, analyzed their formation processes, tested thermodynamic stability, investigated mathematical aspects of quasiperiodic tilings, advanced their understanding through models and simulations, measured electronic and physical properties, and described their practical applications. This microsymposium covers all aspects of research on quasicrystals with emphasis on state-of-the-art experiment and theory and on new and "hot" results with a broad scope.

Session Chairs: Dr Partha Partim Jana and Eva G. Noya

This microsymposium will highlight novel advances in purification, crystallization methodology, Cryo-EM grid preparation and other processes central to successful structure determination.

Session Chair: Miki Senda

Data management is an indispensable component of modern scientific research and a key factor that can ensure reproducibility of experimental results.

This microsymposium will shed light on how structural biology (X-ray crystallography, electron microscopy and small angle scattering) have aided in tackling both bacterial and viral diseases and malaria.

Co-sponsor: Commission on Small-Angle Scattering

Session Chairs: Prof Wladek Minor and Prof Emily Parker

How biomolecules and structural biology tools can contribute to the development of functional materials to meet the UN Sustainable Development Goals such as affordable and clean energy, health, agriculture and recycling.

Co-sponsor: Commission on Small-Angle Scattering

Session Chair: Dr Hiroshi Sekiguchi

Use and quality of models generated by AlphaFold2, RoseTTAFold and similar methods for construct design, phase determination, initial model building and other computational methods in structural biology.

Session Chair: Dr Luigi Vitagliano

Use of Deep Learning & AI to facilitate analysis of large-scale experiments in structural biology.

Session Chairs: Dr Airlie McCoy and José-María Carazo Garcia

Modern methods to validate structures and bound ligands as determined via X-ray crystallography, cryo-EM, MicroED and Integrative Methods

Session Chairs: Dr Dorothee Liebschner and Dr Oleg Sobolev

Modeling multi-subunit protein interations by combining cross-linking and mass spectrometry, SAXS, and other methods.

Session Chair: Dr Dritan Siliqi

Structural information, mainly derived by X-ray crystallography and Cryo-Electron Microscopy, is the quintessential prerequisite for structural-guided drug discovery. However, accurate structural information is only one piece of information necessary to understand the big picture of medical disorders. To provide a rapid response to emerging biomedical challenges and threats like COVID-19, we need to analyze medical data in the context of other in-vitro and in-vivo experimental results. Recent advancements in biochemical, spectroscopical, and bioinformatics methods may revolutionize drug discovery, albeit only when these data are combined and analyzed with effective data management framework

This session will be dedicated to data management systems that will provide integrated information for biomedical researchers.

Session Chairs: Prof John Helliwell and Dr Brinda Vallat

Structures of very large macromolecular assemblies newly obtainable by methods such as Cryo-EM, Cryo-ET and FIB milling of samples.

Session Chairs: Gaya Amarasinghe and Prof Alice Vrielink

Including novel methods for rapid structure-based drug design such as Cryo-EM, new docking methods, fragment screening, etc.

Co-sponsor: Commission on Electron Crystallography

Session Chair: Claudio Ciferri and Dr Sandra-Cowan Jacob

Structures and regulation of enzymes studied by multiple structural biology methods such as X-ray and/or neutron diffraction, SAXS, Cryo-EM and other methods.

Session Chair: Dr Catherine Drennan

Structural biology of viruses, especially by hybrid methods.

Session Chair: Dr Andrzej Joachimiak and Andrew Mesecar

Elucidation of the molecular mechanism of signal transduction by immune receptors/neutralizing antibodies.

Session Chairs: Hyoun Sook Kim

Statistical tools are used in most fields of crystallography. Applications range from data bases and knowledge bases to the phasing of proteins and the validation of structural results. Enormous progress has been made in tools for machine learning.

Session Chair: Dr Tristan Croll

Crystallographic fragment screening is an effective and efficient method to identify new chemical scaffolds for the development of lead compound. The micro symposium will focus on computing and strategy involve in evaluating large number of datasets collected from crystals soaked in mixtures of various compounds to represent fragments of potential drugs.

Session Chairs: Dr Uwe Müller and Justyna Wojdyla

The importance of intermolecular interactions distinguishes the crystalline state from the solution, liquid and gas state. This MS will focus on the computational aspects of these interactions which range from geometrical calculations to the analysis of quantum chemical results. Practical applications include the determination of topological frameworks and graph sets as well as energy calculations and other physical properties.

Session Chairs: Mr Santosh Panjikar and Dr Martin Lutz

The comparison of crystal structures is a non-trivial problem in most fields of structural crystallography. It is necessary to find fundamental laws of symmetry and packing but also in the analysis of multi-crystal experiments and in crystal structure prediction. Also, one of the important applications is the detection of fraud.

Co-sponsor: Commission on Mathematical and Theoretical Crystallography

Session Chairs: Mr Jan Rohlicek and Prof Ma Louise Antonette De Las Penas

In recent years we have seen much progress in the software for powder diffraction. This includes the analysis of the raw experimental data as well as structure solution and refinement. Also, the analysis of structural dynamics has become applicable to a large number of structural questions.

Co-sponsor: Commission on Powder Diffraction

Session Chairs: Dr Brian Toby and Dr Rosanna Rizzi

Session Chair: Dr Charles Ballard and Dr Melanie Kirkham

Crystallographic education in the 21st century is charged with meeting the needs of users ranging from current practitioners to the casual layperson. With improved accessibility to instrumentation, the crystallographic process, and crystallographic topics, the need is greater than ever to deliver a broad selection of modern training materials that promote the learning process of crystallography. Presentations in this session will explore a variety of recent approaches and innovations that foster the learning process of crystallography with topics ranging from formal training modules, hands-on exercises, and virtual resources.

Session Chairs: Prof María Cristina Nonato and Dr Shao-Liang Zheng

Understanding the symmetry of crystals, 1 and 2 periodic arrangements and local symmetry of atoms in a solid are necessary for describing and understanding the physical properties of materials. This is particularly relevant for materials in state-of-the-art applications, such as topological insulators, luminescent, ferroic materials etc. where local or extended symmetry imposes existence conditions to some properties, but also for a fundamental understanding of crystalline matter. Crystalline materials are studied at the graduate and undergraduate levels with increasing frequency, requiring younger students to learn the basics of crystallographic symmetry to understand the properties. A plethora of printed and on-line tools for visualizing, analyzing and understanding symmetry in crystals are being developed in parallel to satisfy the demand. There are, however, few opportunities for the students to learn crystallographic symmetry formally, since courses are scarce, if at all existing in university curricula at the graduate level, being taught partially as part of solid-state physics or chemistry courses. To add more difficulties to the effective teaching of the matter, students from different areas of knowledge need to learn crystallographic symmetry, making different approaches have different effectiveness for different publics. Intensive courses on crystallographic symmetry have been taught in IUCr-sponsored schools and workshops with increasing frequency in all regions for motivated graduate and undergraduate students. But this is not enough to satisfy the demand so increasing attention and improving the quality crystallographic symmetry teaching at the local level is required. The IUCr has recognized the need for better crystallographic symmetry teaching tools, publishing the Teaching Edition of the International Tables for Crystallography Vol A in 2020 and including tools for symmetry analysis and visualization in the on-line version of ITC. The same has been done by software developers, including visualization and symmetry management tools in specific programs. This Microsymposia aims at sharing experiences of teaching crystallographic symmetry for undergraduate and graduate students in all areas of science in exclusive or as part of other courses. It will also allow for sharing the tools used for the purpose and discuss the effectiveness of different teaching approaches for different groups of students, presented for the benefit of the community of Professors and students of all levels.

Session Chairs: Dr John Claridge and A/Prof Inbal Tuvi-Arad

Understanding thermomechanical deformation of engineering alloys at the microscale and below is of central interest to a broad range of industries including transportation and energy. With the ability to measure microstructural and micromechanical response in situ, models can be developed to optimize material processing routes for superior properties and better using existing material systems for enhanced safety and economy. The development and maturation of diffraction microstructure imaging methods over the past 20 years has provided a new tool to understand deformation at the microscale. Specifically, techniques enabling the 3D characterization of lattice orientation and elastic strain fields within individual grains embedded in polycrystals are providing new insights into long-standing questions associated with microstructural evolution and material failure.

This microsymposium aims to provide a venue for the latest developments in diffraction-based micromechanical characterization including the identification of novel deformation mechanisms, connecting diffraction-based measurements to micromechanical modelling, novel microstructural reconstruction methodologies, and novel in situ deformation experiments.

Session Chairs: Ms Ashley Bucsek and Prof Darren Pagan

Functional properties and performance of materials are governed by their microstructure. The interactions between adjacent grains (the neighbourhood) and grain boundaries contribute significantly to mechanical, thermal, and electrical properties in polycrystalline materials (geological, metallic, and ceramic) and are often a critical feature to be controlled during processing. New spatially-sensitive diffraction microstructure imaging techniques are now enabling interactions between grains and grain boundaries, in addition to their formation during processing, to be directly probed along with their influence on material properties. Using these methods, novel insights into physical phenomena of material deformation and function have been gained.

This microsymposium will concentrate on high-lighting 3D microstructural imaging methods to understanding the formation of grain structures and grain boundary character and their influence on material properties.

Session Chairs: Dr Josie Auckett and Dr Jette Oddershede

Over the last 50 years, high pressure research allowed for discoveries in multiple fields of science, with applications ranging from earth science and planetology, condensed matter physics, to the synthesis of new materials. Samples in high pressure devices often appear in the form of a multiphase and multicrystal assemblage within a micro-focused x-ray beam. Such samples fall in between the ideal single-crystal and powder and are inappropriate for conventional crystallographic characterization. In addition, sample microstructures need to be characterized and this requires mapping the orientations and properties of hundreds of individual grains simultaneously.

Recently, new multigrain crystallography and multi-crystal indexing techniques emerged. Both have now been successfully applied to characterize the crystal structures of complex multigrain, multi-phase samples at extreme conditions, as well as to track the hundreds of microstructural elements of materials undergoing processes such as phase transformation and plastic deformation. Despite significant advances, however, these experiments and the processing of such data remain a technical challenge.

Nevertheless, these methods offer great avenues for discoveries in high pressure research. With new updated synchrotron sources, studies of materials under multi-megabar pressures will expand and these materials will require investigating multiple crystals simultaneously. In parallel, multigrain crystallography allows, for instance, for a new approach in the study of phase transformations, the induced microstructures, and the associated mechanisms. Finally, the high-pressure community has developed a great expertise at solving crystal structures under complex environments, and this could cross-feed into the multigrain crystallography community and other fields of science.

This microsymposium aims at bringing together those addressing multicrystal indexings, characterization of new structures and microstructural studies using multigrain crystallography under pressure. We will highlight the latest technical and scientific discoveries and how the methods could be developed and opened towards a broader community.

Co-sponsor: Commission on High Pressure

Session Chairs: Sébastien Merkel and Stella Chariton

Techniques involving electron diffraction or imaging form an important part of the toolkit for the crystallographic characterisation of matter. Electron crystallographic techniques are particularly advantageous when probing structureatthe nanoscaleand below.Significant technological advanceshave enabledthe development of new techniques, as well asthe implementation of methods devised long ago. Such techniques allow much greaterstructuralinformation to be obtained from ever smaller regions of solid matter. This microsymposium will focus on the latest theoretical, experimental and computational methods of electron diffraction and imaging and how they can be applied to advancing crystallographyin the broadest sense.

Session Chairs: Changlin Zheng and Colin Ophus

In almost all crystalline materials there will exist some spatial departure from the average crystal structure, such as due to defects, interfaces, strain or chemical ordering. Mapping how the crystal structure changes at the atomic scale is important for understanding how a material forms and what its properties might be. Electron crystallography, whether using diffraction or imaging, is a very useful tool for such characterisation. This microsymposium will focus on the application of electron crystallographic techniques to map structure at or near the atomic scale, in two or three dimensions. Contributions to this topic onany type ofmaterialsand structures are welcome.

Session Chairs: Jian-Min Zuo and Dr Amelia Liu

New aperiodic structures, incommensurate modulated and composite crystals, quasicrystals and their approximants, continue to be discovered in different systems andunder a wide variety of conditions. In addition to the structure characterization of thesematerials, there is an increasing interest in studying the formation mechanisms of aperiodicstructures, determining the crystallographic relationships between different phases as wellas the role of structural defects.In the absence of single crystals of sufficient size, thestructural study of these complex materialsis often compromised. In this symposium we wish to illustrate the necessary complementaritybetween X-ray powder diffraction and electron microscopy techniques but also the importanceof 3D-ED methods and dynamic refinements to understand the structure of aperiodic materials.This symposium will also cover the "multi-scale study" aspect of these crystals.Focus will be placed not only on solving structure but also on establishing links between relatedstructures and their formation mechanisms in a given material

Co-sponsor: Commission on Aperiodic Crystals

Session Chairs: Prof Louisa Meshi and Prof Joke Hadermann

Electron crystallography has recently experienced an extraordinary development of experimental methods for the determination of three-dimensional structures of crystalline solids. Thanks to that, not only hard, but also soft materials like organic or protein crystals can be studied with the use of electron diffraction techniques. With access to better experimental data, the information about the atomic structure can be extended to include the description of the electronic structure of the material under study. This can be done on various levels of approximation and from different perspectives. Sophisticated periodic quantum chemical calculations might be used to model experimental data or experimental data may challenge quantum theory. Various models of electrostatic potential can be used to support atomic structure refinements or partial atomic charges might be determined directly from diffraction experiment. The session will report most recent developments crossing the borders of electron crystallography and quantum crystallography.

Co-sponsor: Commission on Quantum Crystallography

Session Chairs: Prof Joanne Etheridge and Brent Nannenga

Almost all materials inevitably contain interfaces between different crystallographic phases. In some cases, such as thin films, the material is all interface. Characterising and understanding the crystallography of interfaces are important not only for determining the full structure of a material, but can also provide key information about the structural transformations between different phases. Lattice defects also play an important role and must be characterised to get a full picture of the structures and their transformations. Such knowledge is necessary to explain materials properties, and ultimately, for materials design. This micro-symposium will focus on the experimental characterisation and crystallographic modelling of interfacial and defect structure in any material system, whether soft or hard, ferroelectric thin films, perovskite solar cell devices, precipitate-containing metallic alloys, model bi-crystals...etc Contributions from all forms of diffraction and microscopy (X-rays, electrons, neutrons) are welcome, including new techniques and their applications.

Co-sponsor: Commission on Small-Angle Scattering
Commission on Structural Chemistry, Commission on Neutron Scattering

Session Chairs: Prof Randi Holmestad, Prof Changquan Calvin Sun and Prof Ya-Sen Sun

If an unknown structure exists in a form of single crystal with an adequate size –single crystal X-ray diffraction will be most probably the best method for its structure solution. However, in the last decades, structural research has shifted towards nanosized materials, multiphase alloys and highly disordered materials, including glasses. In these cases, powder X-ray diffractionand/or electron crystallography are the only options for structure solution. However, each method has its disadvantages. Thus, the most powerful tool is combination of these methods,since electrons allow focusing on one small particle and do not suffer from overlapping of reflections and powder X-rays intensities (in most cases) do not change dramatically due to beam damage or thickness of the specimens.This microsymposium will focus onthe development of routines and methods using thecombination of X-raysand electronsfor structure characterizationof materials as well as application of these methods for this purpose.

Co-sponsor: Commission on Synchrotron and XFEL Radiation

Session Chairs: Dr Holger Klein and Dr Stéphanie Kodjikian

Nanoscale magnetic structures at and around hetero-interfaces, domain walls, grain boundaries, dislocations, topological spin structures (e.g. skyrmions), and other defects are important to the design and control magnetic properties and devices. Cutting-edge microscopy/imaging techniques have recently been developed for the characterization of such structures on the 1-100 nanometer length scales, which opens up exciting new opportunities for scientific discovery. This microsymposium will showcase state-of-the-art methods and recent scientific breakthroughs, and address future directions for the imaging of nanoscale magnetic structures in solid-state materials.

Co-sponsor: Commission on Magnetic Structures

Session Chair: Claire Donnelly

Porous materials are known as difficult materials to crystallize and very often they to produce crystals with nanometric ordered domains. Their structure determination is consequently very challenging. Nowadays the combined used of x-ray powder diffractionand 3D electron diffraction, the first one giving a global view of the synthetized sample, the second one furnishing single crystal data on nanometric domains, allows to study these materials in very high detail

Co-sponsor: Commission on Powder Diffraction

Session Chairs: Junliang Sun and Dr Hongyi Xu

Session Chairs: Koji Yonekura and Tamir Gonen

With the modern trend towards miniaturization of electronic components, crystallography is facing the problem of structure analysis of nanosized materials. Functional materials, as MOFs /COFs, molecular crystals, semiconductors, battery materials, nanoparticles and 2D crystals, designed for their particular physical properties, typically do exist as nanocrystals. Whenever a question of structural characterization of nanocrystals rises, electron diffraction becomes an essential method of analysis. In this microsymposium we feature examples of structure analysis of all types of functional materials by electron diffraction alone, or in combination with other techniques. We especially welcome contributions on in-situ and operando studies.

Co-sponsor: Commision on Crystal Growth and Characterization of Materials

Session Chair: Dimitri Golberg and Dr Sebastian Suarez

We expect contributions ranging from novel scintillator crystals for medical imaging techniques (like computed tomography (CT), positron emission tomography or mammography (PET, PEM) and single-photon emission computer tomography (SPECT)) to laser crystals for surgery devices. This session will highlight the recent developments and which of the novel materials are most promising for future application.

Co-sponsor: Commission on Structural Chemistry

Session Chairs: Ms Ewa Grzanka and Mariya Zhuravleva

Crystal growth and characterization of superconductors; diluted magnetic semiconductors; multiferroics; topological insulators, Weyl semimetals,Dirac materials.

Co-sponsor: Commission on Magnetic Structures

Session Chairs: Dr Dharmalingam Prabhakaran amd Rosalba Fittipaldi

Biomineralization is the widespread natural process by which living organisms produce hard, functionalized tissues. Biominerals and biomimetic materials with unique microstructure and excellent functional properties belong to the family of composite organic/inorganic materials. The mechanisms leading to the formation of biominerals involve the presence of the organic matrix as a scaffold in directing the morphology, structure, and functionality of the biomineral itself. Biominerals and their synthetic counterparts, biomimetic materials, are top trending topics in the scientific community because of their importance in the materials sciences and medical fields. Still, natural processes need further investigations to learn from constructional processes of biomineralization and achieve biomimetic materials with special structure and functionality, learning from nature.

Session Chairs: Dr Wolfgang W. Schmahl

Quantum crystallography field intimately relates periodic structure of crystalline materials with the deep understanding of material nature and fundamental properties in light of quantum theory. It involves both application of quantum mechanics to improve crystallographic studies and the implementation of crystallographic results in quantum-mechanical calculations. Constant development of quantum methods and a significant increase in the precision of crystallographic measurements boost the progress of research activities in this area. Studying quantum phenomena at very high pressure is of a great interest for fundamental and applied solid state science. Pressure is a crucial thermodynamic parameter that can substantially reduce interatomic distances (in particular non-bonding contacts) in crystals and in consequence tune their electronic properties. However, experimental charge density studies under pressure are very challenging due to limited access of the reciprocal space shaded by the body of the pressure cell. Hence, novel experimental and conceptual approaches are indispensable to overcome these obstacles. Among them, more accurate scattering factors delivered by quantum crystallographic approaches are, for example, helping to determine more reliably high-pressure atomic structures of studied materials. On the other hand, a wide range of correlated electron phenomena can be effectively tuned by pressure. One of the most spectacular examples is the high-temperature superconductivity (in some exceptional cases in temperature reaching almost room-temperature regime), that can be achieved at pressure extremes. The growing need for advanced materials calls for increased focus on structure-property relationships in strongly correlated electron systems under high pressure.

Co-sponsor: Commission for Quanton Crystallography, Commission on Magnetic Structures

Session Chairs: Dr Rebecca Scatena and Dr Sajesh P. Thomas

Crystallographic studies of materials at high pressure has the unique ability to reveal the structural origins of, or give strategies to optimise, functional properties in next-generation materials. The increasing availability of high-pressure capability at central facilities has led to high-pressure studies on an increasingly-diverse range of materials. Examples include investigations at high pressure that improve understanding of gas uptake in Metal–Organic Frameworks (MOFs) by revealing accessible pores and diffusion pathways, studying order/disorder transitions in metal halide hybrid perovskites to understand defect-dependent charge carrier behaviour, or understanding the strain behaviour of candidate battery materials. Improvements in detector and diffractometer technology means that structurally-complex materials can routinely be measured, while the use of neutrons opens up the study of magnetic materials. In all cases, the study of intrinsic mechanical behaviour and structural instabilities of functional materials that are critical to understand when considering application of new materials in devices.

In this microsymposium we invite contributions where the use of extreme conditions has been important in understanding functionality. This can include mechanical, electronic or magnetic properties using one or more stimuli in-situ.

Session Chairs: Dr Andrew Cairns and Bianca Haberl

Recent developments at dynamic compression platforms at synchrotron sources and X-ray free electron lasers (XFELs) have greatly enhanced capabilities to study materials under extreme conditions of pressure and temperature. The coupling of high-power lasers with highly brilliant X-ray sources has allowed for structural determination in shock compressed samples, revealing discrepancies between material behaviour at different compression timescales. Shock compression techniques have also extended the structural knowledge of materials to the extreme pressure-temperature regime relevant for Earth and planetary science, which is beyond the limit of diamond anvil cell experiments. At the same time, developments in dynamically-driven diamond anvil cells (dDACs) have provided access to the intermediate compression rate regime which is not accessible using traditional static and dynamic compression techniques, where advancements in time-resolved X-ray diffraction diagnostics has opened up the possibility to study phase transition kinetics over a wide range of compression rates.

The ability to study the lattice-level response of dynamically-compressed materials over such a wide range of compression timescales has provided unprecedented insight into material behaviour under dynamic loading. This micro-symposium welcomes contributions which highlight scientific results gained from the combination of time-resolved X-ray diffraction diagnostics with dynamic compression drivers.

Session Chairs: Dr Rachel Jane Husband and Dr Richard James Briggs

Crystallography is important to space research in a wide variety of ways under a huge variety of conditions. This microsymposium will encompass not only planetary geology, from experimentally determining the mineral composition of lunar and Martian rocks to inferring the compositions of other planets in the solar system to predicting those of exoplanets; but also zero/low-gravity crystallisation, with implications for the formation of comets and potential applications from the crystallisation of novel phases to difficult macromolecules. Key methods will include synthesis and diffraction under high-pressure and other extreme conditions, in situ and rapid parametric/combinatorial experiments, and predictive computational studies.

Co-sponsor: Commission on High Pressure

Session Chairs: Tom Runcevski and Tuan Va

Many physical properties depend upon the underlying symmetry of the crystal structure (and therefore electronic structure) of materials. Indeed Pierre Curie (perhaps inspired by Pasteur’s work) noted “C’est la dissymmétrie qui crée le phénomène” in relation to chirality. This line of thought can be extended to other classes of non-centrosymmetric symmetries which underlie physical properties which include, in additional to chirality, non-linear optical activity, piezoelectricity and polar properties. Traditional applications of non-centrosymmetric materials often require specific combinations of properties such as electrically insulating and polar materials for ferroelectrics. However, the phenomena afforded by more unusual combinations, such as skyrmions found in chiral and magnetic systems, and Weyl semimetals among the non-centrosymmetric topological insulators are at the forefront of current research in materials science and have motivated research into increasingly diverse families of non-centrosymmetric materials. This impetus has inspired researchers to turn to more varied strategies to break inversion symmetry (including cation or anion ordering, and magnetic order), and to investigate structure-property relationships in a wider range of non-centrosymmetric materials.

This microsymposium aims to highlight recent advances in design and characterisation methods, and in understanding the physical consequences of broken inversion symmetry, in these complex systems.

Co-sponsor: Commission on Magnetic Structures

Session Chairs: Emma McCabe and Dr Anthony Phillips

The search for new and improved solid-state ionic conductors (SSICs) is one of the most active and important fields in materials chemistry, driven by the key role they play in technologies as diverse as solid-state batteries, fuel-cell, sensors, carbon capture compounds and hydrogen storage. Solid-state ionic conduction is also a crucial aspect of mineral formation as well as subsolidus synthesis and post-synthetic modification in materials chemistry. The paradoxical chemical and structural requirements of SSICs are challenging: long-range order to provide a mechanically stable framework, together with short-range disorder so that selected atoms can migrate through it. Rational design and optimisation of SSICs depend on a detailed understanding of the atomic-scale architectures that allow this paradox to be resolved.

This microsymposium will cover all structural aspects of solid-state ionic conduction, emphasising the insights that can be obtained by careful crystallographic analysis and the progress that can be made by applying crystallographic design principles. This includes but is not limited to: 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 allied methods.

Session Chairs: Prof Stephen Skinner and Abbie Mclaughlin

This microsymposium will highlight particularly complex and difficult mineral and inorganic material structures. This includes large unit cells, superstructures and incommensurate modulations, nanocrystals, stacking faults, local disorder, mixed/partial occupancies, pseudosymmetry, and other challenging problems. Such structures are often underdetermined by conventional crystallography and can only be solved with the help of other experimental and/or theoretical methods.

Co-sponsor: Commission on Quantum Crystallography, Commission on Electron Crystallography

Session Chairs: Dr Yong-Jae Lee

This microsymposium will gather persons who are using approaches based on the structural knowledge of minerals and related materials to find new methods (or to improve present expertise) when dealing with problems related to pollution, public health, sustainable resources, waste disposal, recycling of materials, CO2 capture and any other issue relevant to sustainable development.

Session Chairs: Carlotta Giacobbe and Nathan Webster

This microsymposium will highlight events and outcomes of the Year of Mineralogy 2022, proclaimed by the International Mineralogical Association (IMA), approved by UNESCO and included as part of the initiatives of the International Year of Basic Sciences for Sustainable Development (IYBSSD 2022).

Mineralogy is a very active and rapidly evolving field with a tremendous impact on many facets of our society. While constituting the basis of geology, which underpins and supports the whole earth science system, mineralogy is closely related to crystallography. Mineralogy is essential in searching for new sustainable resources (strategic metals, etc.) either in natural deposits or from human-made products. Minerals affect environmental quality and control environmental pollution, and offer a promising approach for carbon capture and storage, which could help to reverse climate change. Mineral diversity and evolution is an indicator of planetary evolution including the apparition of life, thus representing a key factor in planetary sciences including the remote search for life in exoplanets. The mineral world also interacts with the biosphere, and this often involves major implications for human health.

This session encompasses any kind of contributions in the study of magnetic materials, where magnetic symmetry, in any of its possible forms (magnetic point groups, magnetic space groups or magnetic superspace groups) constitute a fundamental basis or a fundamental tool of the work being presented. This MS also aims to gather all new developments, theoretical or applied, in the field of magnetic symmetry, including nomenclature, standardization, software development, applications, etc. Contributions based on representation analysis, in conjunction or not with magnetic symmetry groups, are also welcome.

Co-sponsor: Commission on Neutron Scattering

Session Chairs: Dr Françoise Damay and Dr Ovidiu Garlea

The technological interest of many new materials is based on physical properties which are closely related to their magnetic behaviour. For this reason, it is essential to relate magnetic orderings to these physical properties at the microscopic level, as well as their responses to external factors such as temperature and pressure, among others. Neutron diffraction is the most direct and flexible probe for this purpose, which often takes advantage of polarized neutron beams. Muon-spin spectroscopy and X-ray magnetic resonant scattering methods are also of growing importance. The analysis and interpretation of magnetic diffraction data is a significant challenge, which often requires the use of magnetic symmetry groups and representational analysis. The aim of this session is to show the potential of magnetic diffraction when combined with advanced analytical tools.

Co-sponsor: Commission on Neutron Scattering, Commission on Powder Diffraction, Commission on Magnetic Structures, Crystal Growth and Characterization

Session Chairs: Dr Dmitry Khalyavin and Clarina Dela Cruz

Short-range magnetic correlations play a key role in a variety of material systems ranging from quantum materials to magnetic functional materials. When probed by neutrons or resonant x-rays, magnetic local order gives rise to diffuse scattering, which is rich in information but can be challenging to analyze and model. This session highlights the latest research on materials and methods relevant to diffuse scattering from magnetic local order. Material systems of interest include frustrated magnets, quantum spin liquids, Kitaev materials, strongly correlated electron systems, dilute magnetic semiconductors, magnetocalorics, superatomic magnetic solids, and more. Methods of interest include neutron and x-ray magnetic scattering, magnetic pair distribution function, reverse Monte Carlo, and other experimental or computational techniques for studying short-range magnetic order.

Co-sponsor: Commission on Neutron Scattering

Session Chairs: Dr Joe Paddison and Ms Alannah Hallas

Aperiodicity has been known in magnetic systems for more than sixty years. Magnetic spin waves were then described by a periodicity incommensurate to that of the underlying lattice. Although the two lattices were first considered independent, it soon became clear that their coupling is critical in certain classes of materials such as multiferroics. Much progress has been achieved meanwhile in this field fueled by emergent techniques and methods. Recently, long-range ferromagnetism was first observed in real quasicrystals. This session will be devoted to novel experimental and theoretical aspects of magnetic order in quasicrystals, approximants, and incommensurate systems, and to the interplay of symmetry in interactions and properties.

Co-sponsor: Commission on Aperiodic Crystals

Session Chairs: Ryuji Tamura and Margarida Henriques

Magnetism has been at the core of research on developing multifunctional materials. These materials have been of interest not only to condensed matter physicists, but also to solid-state structural chemists, theoreticians among other. Neutrons are a unique probe which helps in understanding not only the crystallographic but magnetic structure as well, and in cases of cation-ordered perovskite, cation distribution too. This micro symposium (MS) invites contributions of studies of crystallographic and magnetic structures on new and novel perovskite materials exhibiting interesting physical properties. Neutrons as a tool for establishing structure-property correlations will be motivating this MS. Recent developments in applying magnetic crystallography in resolving understanding of the magnetic phenomenon are highly anticipated. Studies under extreme conditions of temperature, pressure and magnetic fields are also called for in this MS for wider participation of colleagues working on materials exhibiting unique structural and magnetic properties under these extreme conditions.

Co-sponsor: Commission on Powder Diffraction

Session Chairs: Prof A. Sundaresan and Fabio Denis Romero

Molecular based magnets have generated intense interest in recent years because of the technological possibilities that they suggest in so-called Molecular Spintronics. These are materials that combine some of the intrinsic properties of molecular solids (nanoscopic size, low density, synthetic versatility, optical transparency, and so on) with the presence of one or more physical properties of practical utility. Among the properties that have stimulated the greatest interest, we can highlight optical as well as electrical and magnetic properties – regardless of whether the latter be cooperative (such as ferromagnetism or superconductivity) or non-cooperative (super-paramagnetism, spin glass). The systems that generate the greatest attention are those molecular materials that can be converted reversibly between two states, with concomitant variations in some of the properties of interest, under the action of an external stimulus such as light, pressure, temperature, or electric or magnetic fields. Recently materials have been obtained which combine electric and magnetic properties (molecular multiferroics), optical and magnetic properties, and even magnetic properties in systems with intramolecular electron transfer. It could be expected that in these multifunctional materials a mutual influence could exist – a synergy – between the properties involved, making possible the development of nanoscopic devices such as molecular switches or spin filters.

Co-sponsor: Commission on Neutron Scattering

Session Chairs: Dr Richard Mole and Prof Annie Powell

Molecular based magnets have generated intense interest in recent years because of the technological possibilities that they suggest in so-called Molecular Spintronics. These are materials that combine some of the intrinsic properties of molecular solids (nanoscopic size, low density, synthetic versatility, optical transparency, and so on) with the presence of one or more physical properties of practical utility. Among the properties that have stimulated the greatest interest, we can highlight optical as well as electrical and magnetic properties – regardless of whether the latter be cooperative (such as ferromagnetism or superconductivity) or non-cooperative (super-paramagnetism, spin glass). The systems that generate the greatest attention are those molecular materials that can be converted reversibly between two states, with concomitant variations in some of the properties of interest, under the action of an external stimulus such as light, pressure, temperature, or electric or magnetic fields. Recently materials have been obtained which combine electric and magnetic properties (molecular multiferroics), optical and magnetic properties, and even magnetic properties in systems with intramolecular electron transfer. It could be expected that in these multifunctional materials a mutual influence could exist – a synergy – between the properties involved, making possible the development of nanoscopic devices such as molecular switches or spin filters.

Co-sponsor: Commission on Crystal Growth and Characterization of Materia

Session Chairs: Prof Michael Shatruk and Je-Geun Park

In the middle of the last century, Igor Dzyaloshinskii and Toru Moriya introduced antisymmetric exchange to explain a small ferromagnetic moment in typically antiferromagnetic crystals (Dyaloshinskii-Moriya interaction, DMI). Since that time the antisymmetric exchange has become a key ingredient in the study of magnetic materials. The session will cover a broad range of magnetic phenomena where antisymmetric exchange plays a central role. These include spin driven electric polarization in type II multiferroics, magnetic skyrmions, merons and other topological spin textures in non-centrosymmetric crystals and at interfaces in thin film heterostructures. It will also include the recently proposed generalization of antisymmetric exchange for materials with electric dipole ordering such as ferroelectric and antiferrolectrics (electric DMI). This implies that any effect driven by the magnetic DMI should have the corresponding counterpart in systems with electric dipole ordering, form simple canting to the polar topological phases.

Co-sponsor: Commission on Inorganic and Mineral Structures, Commission on Neutron Scattering

Session Chair: Prof J. Manuel Perez-Mato

Topologically nontrivial states have been widely recognized in crystalline compounds, ranging from the topological insulators and the Dirac/Weyl semimetals in electronic states to the chiral solitons and skyrmions in the magnetic materials. It has been widely recognized that the underlying crystallographic and magnetic symmetries are crucial for the classification of the nontrivial topologies. This micro symposium (MS) is devoted to the systems with the nontrivial topologies with the special emphasis put on the role of underlying crystallographic and magnetic symmetries. Both experimental and theoretical aspects of topological matter will be discussed in this MS. Experimental approaches covered in this session include (but are not restricted to) small angle neutron scattering, Lorenz transmission electron microscopy and selected area electron diffraction.

Co-sponsor: Commission on Small-Angle Scattering

Session Chairs: Prof Luis Elcoro and Dr Anna Sokolova

Magnetic systems are dubbed geometrically frustrated, if geometrical arrangement of constituent atoms does not allow all magnetic interactions to be merely satisfied. As a consequence a manifold of states have similar energy and compete for realization. This session is devoted to novel materials where geometrical frustration emerges. We welcome contributions on new exotic magnetic states, on unconventional dynamics and scrutiny of mechanisms leading to selection of such states. The session is intended for a broad community interested in fundamental knowledge about the solid state and competing collective phenomena in nature.

Co-sponsor: Commission on Neutron Scattering, Commission on Crystal Growth and Characterization of Materials

Session Chairs: A/Prof Ben Frandsen and Dr Oksana Zaharko

Keywords: program, iron compounds, oxides.

Co-sponsor: Commission on Structural Chemistry

Session Chairs: Prof Artem Oganov and Dr Peter Spackman

Keywords: synthesis, crystal structure, properties.

Session Chairs: Prof Kang Min Ok and Chandrasekar Rajadurai.

The main problem in comparative crystal-chemical studies [1] is a big number of possible representations describing the same crystal structure obtained from different sources, laboratories, or external conditions. To attract a broad audience, the micro-symposium will discuss all possible approaches to the comparison of simulated and experimental crystal structures in big datasets [2] by different equivalence relations. The obstacles for continuous metrics on crystals appear already in the simpler case of lattices: numerous similarity distances depend on manually chosen parameters that affect the outputs of algorithms [3]. Of special interest are applications of computational techniques that will allow the comparison of massive datasets at the scale of the Inorganic Crystal Structure Database and Cambridge Structural Database whose periodic crystal structures require more than 200 billion pairwise comparisons, see [4, section 7].

1. Sacchi et al. Same or different - that is the question. CrystEngComm 22 (43), 7170-7185, 2020.
2. Pulido et al. Functional materials discovery using energy-structure maps. Nature 543, 657-664, 2017.
3. Andrews et al. A space for lattice representation and clustering. Acta Cryst. A 75 (3). 593-599, 2019.
4. D.Widdowson et al. Average Minimum Distances of periodic point sets are fundamental invariants for mapping all periodic crystals. MATCH Comm. Math. Comp. Chem. 87, 529-559 (2022).

Session Chairs: Prof Marjorie Senechal and Dr Vitaliy Kurlin

The interest in materials with diperiodic (layer) or monoperiodic (rod) symmetry, is constantly growing due to their outstanding properties and possible technological applications. Besides these type of materials, other crystalline structures such as domain interfaces, twins, bicrystals, polymers, nanotubes, thin films, two-dimensional sections and projections of three-dimensional crystal structures can also be described by rod and layer groups. The micro symposium will focus on the role of symmetry in the studies of crystallographic, structural and physical properties of materials with subperiodic symmetry.

Session Chairs: Prof Ivanka Milosevic and Dr Gemma de la Flor

In recent years, both discrete and continuous symmetry have been largely applied to develop the machine learning potential, classify topological materials, and investigate crystal-structure relationships and phase transitions. The microsymposium will focus on crystallographic symmetry as a tool to guide contemporary computational materials research under both ambient and extreme conditions. Of special interest are topics related to the development and application of computational techniques from group theoretical approach, analysis of crystal-structure relationships by symmetry relations of crystallographic groups, phase determination and transitions under extreme condition, and their potential applications in functional materials studies such as topological electronics/phononics, piezoelectrics, and ferroics.

Co-sponsor: Commission on High Pressure

Session Chairs: Dr Gemma de la Flor and Prof Leopoldo Suescun

This micro-symposium will aim at highlighting recent development in solving structure of different classes of biomolecules including proteins, nucleic acids and carbohydrates. Numerous recent developments in solid-state NMR spectroscopy have enabled an array of new insights regarding the structure, dynamics, and interactions of biomolecules, providing structural and dynamic information complementary to the data accessible by other means. Solid-state NMR enables the study of samples lacking a crystalline lattice and featuring static as well as dynamic disorder. Recent applications of biomolecular solid-state NMR highlight its complementarity with other structural biology techniques, such as cryo electron microscopy, solutionstate NMR, and X-ray crystallography. Traditional examples of application of solid-state NMR include lipid bilayer membranes and membrane proteins in a lipid bilayer environment and studies of protein misfolding and aggregation disorders, where NMR provided essential structural data on oligomers and amyloid fibril aggregates. This micro-symposium is to focus of recent applications of solid-state NMR concurrently with other computational and experimental tools to a growing array of biological assemblies, ranging from nonamyloid protein aggregates, protein–protein complexes, viral capsids, nucleic acids and carbohydrates. Multidimensional magic angle spinning (MAS) NMR revealed three-dimensional structures, including many that had been inaccessible by other structural biology techniques. Equally important insights in structural and molecular biology derive from the ability of solid-state NMR to probe information beyond comprehensive protein/carbohydrate/nucleic acid structures, such as dynamics, solvent exposure, protein–protein interfaces, and substrate–enzyme interactions. The symposium is to be co-organised with other commissions focussing on bio-macromolecular structure determination (CBM).

Session Chairs: Frances Separovic and Markus Weingarth

The interface between crystallographic data and other experimental data is becoming increasingly important as the characterisation of challenging materials advances. This includes complementary techniques, such as NMR, as well as a wide array of experimental methods as varied as spectroscopy and melting points. This microsymposium will explore the challenges as well as the potential in combining crystallographic data with data from other experimental methods. The advances in experimental tools have been complemented by development of novel computational methods aimed at calculation of NMR structural and dynamic parameters as well as novel machine learning protocols for predicting chemical shifts with accuracy close to those based on DFT calculations.

Session Chairs: P.K. Madhu and Yusuke Nishiyama

This micro-symposium will aim at highlighting complementarity of NMR methods and other structural tools in structure determination of molecular solids and complex functional materials. The main idea of the symposium is to bring communities across the whole plethora of structural tools to explore complementarity of spectroscopic, diffraction and computational methods to elucidate both structure and functional properties of different classes of materials. Particular areas of focus will include elucidation of polymorphism, structural transformations and predicting of properties of functional materials using a combined application of NMR, X-ray/electron diffraction and computational tools. NMR crystallography has been indispensable in understanding of polymorphism and phase transitions in molecular organic solids, subject of considerable interest in academic and industrial research. In addition, along with a wide range of spectroscopic and computational tools, NMR provided unique insight into the molecular and atomic level origins of properties of organic/inorganic hybrid framework and oxide materials (MOFs, ion-conducting oxides, zeolites, layered double hydroxides, complex oxide phases) related to order/disorder transitions and mobility at different time and length scales. This micro-symposium will focus on such examples with a view of attracting a wide community of scientist working across different disciplines.

Co-sponsor: Commission on Structural Chemistry, Commission on Electron Crystallography

Session Chairs: Dr Doris Braun and Prof Sharmarke Mohamed

Neutron scattering using polarised neutron beams brings unrivalled capability for new insights into structure. Modern materials are increasingly disordered, and the intersection of new polarized neutron beam capabilities and instrumentation with complex systems has brought an exciting new era in structural analysis. This microsymposium will feature polarised neutron scattering used to understand structure from the short range using pair distribution methods through to the ultra long range. Materials and systems under study will include strongly correlated electron systems such as multiferroics and superconductivity, skyrmion lattices, complex large scale magnetic structures, and spin spiral states, as well as dynamic nuclear polarization facilitated hydrogen rich structure analysis.

Co-sponsor: Commission on Magnetic Structures

Session Chairs: Dr Grace Causer and Andrew Wildes

Advances in neutron tools and instrumentation brings the capability to study processes and materials undergoing change. For energy storage and delivery systems, neutrons also offer large advantages in elemental contrast for tracking charge and energy carriers, as well as penetration into whole systems and devices. This symposium will feature the use of neutron tools to study energy material change and processes across a range of length scales, and also within functioning devices. Batteries, fuel cell and porous separation materials, membranes for green hydrogen production and components for electrolysis.

Co-sponsor: Commission on Crystallography of Materials, Commission on Powder Diffraction

Session Chairs: Dr Fabrizia Foglia and A/Prof William Brant

An important topic for chemical crystallography, related to kinetics and process changes, also gaining steam through carbon capture and sequestration.

Co-sponsor: Commission on Structural Chemistry, Commission on Crystallography of Materials

Session Chairs: Prof Valeska Ting and Dr Kevin Stone

Nuclear structure and symmetry is the basis for determining and refining magnetic structure, leading directly to controlling the physical properties of many new technologically interesting materials. The determination of magnetic structure and response to factors such as temperature and pressure underpin the advancement of future technologies. Neutron diffraction is essential for this, but also challenging, requiring magnetic symmetry groups and representational analysis. The aim of this session is to showcase the potential of magnetic diffraction in combination with advanced analytical tools.

Co-sponsor: Commission on Magnetic Structures, Commission on Growth and Characterization of Materials

Session Chairs: Dr William Ratcliff and Dr Arsen Goukassov

Total scattering using X-rays, neutrons and electrons can provide invaluable insights into the atomic and magnetic structures of nanoscale, disordered and glassy materials, and how they evolve as a function of time and parameters such as chemical environment, temperature, pressure, and field. This information is vital to understanding the function of varied technologically important and scientifically interesting materials. This MS welcomes all contributions where total scattering (PDF analysis) is applied to the study of nanoscale and disordered materials.

Co-sponsor: Commission on Synchrotron and XFEL Radiation, Commission on Nuetron Scattering

Session Chairs: Prof Andrew Goodwin and Dr Daniel Olds

Modern X-ray and neutron instrumentation is capable of probing materials syntheses in wide a range or environments, such as hydrothermal, mechanochemical, microwave, high pressure, fluxes and melts, and over a wide range of timescales. Such in-beam studies can provide detailed information on formation, intermediates, and growth rates for nanomaterials, powders and crystals. This data provides mechanistic insight and can aid the rapid optimization of syntheses and growth process. It complements computational approaches to materials synthesis by design and traditional synthetic studies. This MS welcomes submissions covering all aspects of materials synthesis and growth using in beam methods.

Co-sponsor: Commission on Crystal Growth and Characterization of Materials

Session Chairs: Prof Karena Chapman and Dr Poul Norby

Phase transitions as a function of temperature, pressure or field, are ubiquitous and often coupled to significant and technologically useful changes in physical properties. Understanding the nature of transitions at both a local and average level is key to the control by design of a material’s properties. X-ray and neutron diffraction, diffuse scattering and spectroscopy play vital roles in understanding the structure and dynamics associated with transitions, and symmetry based tools provide a framework for their analysis. This MS welcomes contributions on any aspect of phase transitions studied by X-ray and/or neutron scattering.

Co-sponsor: Commission on Crystallogtaphic Teaching

Session Chairs: Prof Branton Campbell and Prof J. Paul Attfield

Powder diffraction is used extensively in a wide range if disciplines and research areas to provide at times unique and vital structural information about possibly complicated polycrystalline, multiphasic real materials. This includes dealing with amorphous or nanocrystalline materials as well as microstructural and strain aspects. This is quite distinct from the realm of ideally imperfect single crystals with only a single phase that most crystallographers focus on. This and the rather limited information content of a typical powder diffraction pattern, when compared to that of a single crystal diffraction experiment, results in a number of pitfalls for many crystallographers when they start doing powder diffraction. This can, unfortunately, result in the over interpretation of results or the publishing of powder diffraction measurements that do not support the claims of the greater study. This microsymposium will highlight the most serious of these pitfalls and limitations and look at the use of pdCIF, and training tools, to facilitate an improvement in the quality of published powder diffraction results.

Co-sponsor: Commission on Crystallogtaphic Teaching

Session Chairs: Dr Cora Lind-Kovacs and Prof David Bish

Modern X-ray and neutron scattering methods are capable of generating very large amounts of data as a function of time or other process variables such as temperature, pressure, field, illumination, state of charge or chemical environment. This presents new opportunities for scientific advancement, but it also poses many challenges. The challenges include real time “on the fly” experiment optimization as data is collected, the efficient analysis of large data volumes, data analysis to supplement data that cannot be measured and the examination of large sets of results to extract patterns and scientific insight. This MS will focus on methodologies for the use of data science technology in measurement and/or analysis in crystallography, and reports on scientific findings revealed by the application of data science to structural analysis. Submissions covering all aspects of data/results from total scattering, powder diffraction and single crystal studies as it pertains to the aforementioned challenges are welcome.

Co-sponsor: Commission on Small-Angle Scattering

Session Chairs: Dr Daniel Olds and Manabu Hoshino

X-ray and neutron powder diffraction play an important role in quality control for industries such as metals manufacturing, mining, and cement production, where issues such as phase identification and quantification are of great importance. They are also of great importance in studies of stress, texture, and failure in engineering components. Here the penetrating power of neutrons and high energy X-rays enables non-destructive approaches, including spatially resolved methods.

Co-sponsor: Commission on Neutron Scattering

Session Chairs: Dr Matthew R. Rowles and Prof Anna Paradowska

Quantum crystallography (QCr) is aiming at understanding the nature and properties of crystalline materials within the frame of quantum theory. It is still rapidly evolving field, with many new ideas appearing proposing how to tightly bind quantum mechanics based theory with experimental diffraction or scattering data. New type of experimental data are to be included in to the QCr methodology. New theoretical frameworks to model experimental data are proposed. New theoretical methods of electron density analysis in real space and of periodic wave function determinations are developed. The session will report on all these recent advances in QCr.

Session Chairs: Dr Alessandro Genoni and Dr Anna Krawczuk

The ultimate goal of quantum crystallography (QCr) is to understand the nature of studied crystalline materials deeply enough to be able to predict its physicochemical properties and to use that knowledge to design new materials having desired properties. The session will report on quantum crystallography studies of various kinds of materials like ferroelectrics, semiconductors, thermo-responsive materials or materials exhibiting interesting chromic or optical properties. Research on pharmaceutically relevant crystalline materials will also be presented here, with the focus on bioavailability, thermodynamic stability or polymorphism.

Session Chairs: A/Prof Marlena Gryl and Prof Parthapratim Munshi

Quantum crystallography is rapidly evolving towards more and more reliable modelling of electronic spin densities of various materials. The modeling either complements experimental results or is intrinsic part experimental data analysis and interpretation. Within the latter approach it become possible to extract spin density and information on magnetic properties directly from such experiments like high-resolution X-ray diffraction, unpolarized neutron, polarized neutron diffraction and Compton scattering. A significant progress has been also made in prediction of magnetic interactions and magnetic structures in crystalline materials based on various ab initio methods such as density function theory and dynamical mean-field theory.

New developments in methodology and results of applications of these methods to diverse magnetic systems where the quantum crystallographic methods are crucial for understanding their experimentally determined magnetic structures and magnetic properties will be presented during the microsymposium.

Co-Sponsor: Commission on Magnetic Structures

Session Chairs: Dr Nicolas Claiser and Dr Yoshiharu Sakurai

Since its beginning, crystallography has contributed enormously to the field of structural chemistry, mostly by delivering three-dimensional (3D) atomic structures of crystalline materials and the molecules constituting them. However there is more to be done. 3D structures should be just the beginning of structural analysis. Nevertheless even here, geometric information obtained from routine X-ray crystallography studies can be improved with the help of quantum crystallographic approaches like HAR or TAAM refinements, especially in case of hydrogen location. Structural chemistry is intimately related with characterization of bonding, where geometrical analysis is just the prelude to deeper insights. To go further, access to the electron density or wave function is needed, either experimental or theoretical, or even better a combination of both theory and experiment. Thus application of a plethora of methods characterizing interatomic and intermolecular interactions is possible, like QTAIM, electrostatic potential, NCI, ELF, to name a few. Ultimately, one can observe how chemical bonds are being formed during chemical reactions by recording changes in electron density distribution.

This microsymposium will be a hub for structural chemists who go beyond geometry analysis, and include more sophisticated approaches to interpret diffraction data and characterize bonding interactions. We will include research that contributes to the understanding of the intrinsic properties of chemical bonds, reaction intermediates and extreme chemical bonding states derived via quantum crystallography, and also challenging research that directly observes chemical reaction processes at the valence electron density distribution level.

Commission on Powder Diffraction, Commission on Structural Chemistry

Session Chairs: Dr Daisuke Hashizume and Prof Simon Coles

Obtaining reliable three-dimensional (3D) atomic structures of biological macromolecules is still challenging. Especially, when possible electronic effects occurring in macromolecules or energy of interactions are to be drown on the basis of atoms positions. To support experimental

determination of 3D structures many new approaches appeared, particularly ones based on quantum mechanics and electron density modelling. In extreme cases, for experimental diffraction data of such high-resolution and high-quality, information on electronic structure can be extracted directly from the data using quantum crystallographic approaches. Having reliable atomic structures, various quantum and electron-density based analyses might be performed to understand how biomacromolecules functions. The session will report on recent developments in and biologically relevant results of quantum biocrystallography.

Co-sponsor: Commission on Biological Macromolecules

Session Chairs: Prof Benoit Guillot and Kennet Merz

The manipulation of contrast in small-angle scattering can simplify the analysis of complicated multi-component systems and reduce model ambiguity by pinpointing the arrangement of subunits in a multicomponent system. Neutron contrast of biological relevant molecules can be altered through selective deuteration or through the modulation of H2O/D2O ratios in the buffer solution, and together these approaches can reveal the internal structure of a multi-component system at low-resolution. Today, recombinant DNA technology allows the deuteration of proteins and nucleic acids from any organism, creative deuteration of molecules such lipids and detergents has opened new approaches in experimental design, advances in instrumentation has resulted in higher data quality, and new software developments allows the optimisation of structural models. These advances have enabled SANS to evolve beyond binary complexes to the study of membrane proteins, large multicomponent complexes, and even the whole cell. Further, when combined with data from techniques such as small-angle X-ray scattering, crystallography, nuclear magnetic resonance and electron microscopy, SANS can provide important details in the determination of the structure and function of molecules in solution. This microsymposium will showcase the use of SANS in understanding biological function, organisation of molecules in the cell and the molecular basis of disease.

Co-sponsor: Commission on Neutron Scattering

Session Chairs: Dr Volker Urban and Dr Andrew Whitten

Small angle scattering in combination with in situ deformation gives unique and unprecedented insight into shear and extension induced structures in a variety of soft materials. Over the last several decades in situ deformation small angle scattering measurements have been broadly impactful on fundamental scientific understanding of structure-function relationships and direct industrial applications in colloids, soft matter, polymers, biology and other fields. Whether studying shear induced liquid crystal ordering, orientation in polymer composites, shear thickening in colloidal suspensions, or shear banding in wormlike micelle solutions in operando measurements have been critical to elucidating the effect of deformation on these materials. In this microsymposium we will explore recent advances enabled by combined rheology and scattering measurements. While there are some commercially available products to enable some simultaneous rheology and small angle scattering measurements, many experiments still rely on custom equipment specific to the application. Recent developments include use of microfluidics and capillaries for neutron experiments, and development of a blow molding device for x-ray beamlines. The two speakers that we propose to invite highlight the development of such novel instrumentation for the purpose of understanding polymer composites in biaxial extensional flow and flow induced structural transitions in self-assembled systems.

Session Chairs: Katie Weigandt and Dr Wei-Tsung Chuang

Lipids are essential biomolecules that are key components in nature’s own functional materials and essential nutrients in food. For instance, they form the backbone of cells, defining their geometry and related microenvironments. Because of their versatile structural properties, they are widely employed as building blocks for innovative materials in food, drug delivery and biotechnology. Their structural analysis from the angstrom to the micrometer range lies at the core of the material design and is also fundamental for their further biological understanding. This analysis strongly relies on in situ and in operando small- and wide-angle x-ray and neutron scattering techniques. The aim of the symposium is to connect scientists from diverse backgrounds with common interest in the design, characterization and application of lipid-based materials, such as physicists, chemists, pharmacists and food scientists. The symposium will create a broad international platform to discuss challenges in the online characterization of structures and dynamics in lipid-based materials, and contribute to the further interdisciplinary development of this growing field of research. The focus on advanced scattering and diffraction techniques will help young scientists to expand their knowledge on the potential of neutron and x-ray techniques for these materials.

Session Chairs: Livia Salvati Manni and Stefan Salentinig

Lens-less techniques such as Coherent Diffraction Imaging (CDI) allow us to probe matter in 2D and 3D and can cover a wide range of areas in a broad range of fields from life science to materials science. The principle of this technique consists of illuminating a sample with a coherent beam and using phase retrieval algorithms to reconstruct the object from the scattered beam, which can consist of X-rays or electrons. In the case of X-rays, low emittance and high brightness third and fourth generation synchrotron storage rings have improved the power of probing matter using coherent X-rays, pushing the resolution to the order of nanometers in imaging techniques. Crystalline materials can be mapped through CDI in the Bragg geometry (Bragg-CDI), providing information around deformation, strain, defects, and shape of nanoparticles under several conditions such as in situ and operando. In raster scanning X-ray microscopy, ptychography imaging is employed to extend objects in a 2D map, in which there are overlapped regions that are reconstructed to obtain the shape, or electronic density of objects. Lens-less techniques can also be very powerful when applied to electron crystallography, as they offer the possibility to generate images free from lens aberration effects and thus, in principle, can provide the highest possible spatial resolution (i.e. sub-angstrom) without the use of expensive aberration correctors.

This microsymposium will focus on the recent progress in the development of lens-less imaging techniques realized with X-ray and electrons (coherent diffraction imaging, ptychography and other related techniques), including technical developments (eg sample environments, fast detectors, new advanced algorithms) and practical applications for visualization of non-crystalline and crystalline nanostructures.

Co-sponsor: Commission on Synchrotron and XFEL Radiation, Commission on Diffraction Microstructure and Imaging, Commission on Electron Crystallography

Session Chairs: Dr Carla Polo and Tatiana Latchevskaia

Solution scattering has established itself as a valuable tool for characterization of biomolecular structure and dynamics. A multitude of methods developed for predicting solution scattering intensities from atomic structure allow their seamless integration with other types of experimental data. The use of these methods assumes both accuracy and reproducibility of the experimental scattering data, as well as high fidelity with which they can be predicted from the atomic coordinates. The Micro-Symposium on Standards and Validation in Biomolecular SAS and Integrative Methods will highlight standards and best practices for collection, presentation, and validation of highest quality experimental scattering data, as well as use of such data within integrative modeling approaches, with emphasis on both internal and cross-validation to minimize model overfitting.

Session Chairs: Alexander Grishaev and Dina Schneidman

Advances in manufacturing represent an international goal in enabling an improved global economy, increasing productivity, and creating new products and industries. As a suite of disruptive technologies, additive manufacturing (AM) has realized its transformative potential to impact many industrial sectors through performance gains, weight savings, and rapid part customization and delivery. However, AM technologies' widespread qualification, certification, and utilization face barriers associated with a lack of fundamental understanding of the microstructural evolution under the extreme nonequilibrium AM fabrication conditions. Knowledge required to foster such an understanding is essential for establishing the material-processing-structure-property relationship of AM materials. These tasks, however, are nontrivial and demand us to develop and use the most advanced materials characterization tools over a broad range of time and length scales.

Due to their time resolution and high penetration power, synchrotron and neutron scattering methods have received significant attention in the ever-expanding field of AM. This symposium aims to provide an international forum to share, spread, and promote exciting ideas and the progress of AM materials and process characterization using these methods. The emphasis is on the state-of-the-art in situ investigation. Abstracted are requested but not limited to in the following areas:

1. Time-resolved scattering and diffraction of the AM process
2. Structure and microstructure evolution during post-build heat treatment
3. Residual stress measurements and their model validation
4. Spatially resolved measurements at different length scales, including microdiffraction and microtomography
5. Mechanical behavior characterization, including deformation, fatigue, and fracture
6. Additive manufacturing inspired machine learning methods

Co-sponsor: Commission on Crystallography of Materials

Session Chairs: Dr Fan Zhang and Greta Lindwall

Engineering and designing foods to target the growing worldwide population is becoming an important aspect of food manufacturing. Understanding the crystalline structures of our current foods at their atomic-, nano- and micro- length scales can help manufacturers produce new and innovative products. This microsymposium will focus on demonstrating the role that X-ray and neutron scattering techniques play in the characterization of foods. The session will highlight examples that might include: diffraction, SAXS/SANS and USAXS/USANS together or independently.

Session Chairs: A/Prof Elke Scholten and Fernanda Svaikauskas

Nucleation and crystal growth are essential parts for both crystal structure determination and the application of crystalline materials. Understanding and controlling nucleation and subsequently crystal growth remains a challenge for many compounds. In this microsymposium a bridge will be built between the crystal grower community and those areas where the ability to grow (molecular) crystals confirms or dismisses the underlying chemistry, enables the discovery of new, possibly patentable, crystal forms and also plays an important role in the industrial production of enantiopure compounds from racemates.

Co-sponsor: Commission on Powder Diffraction, Commission on Crystal Growth and Characterization of Materials

Session Chairs: Dr Lauren Macreadie and Dr Nils Nöthling

The crystalline state is the most used and most important solid form of active pharmaceutical ingredients (API). This symposium will provide a forum to discuss the crystal structures and properties of crystalline APIs, including various forms of salt, cocrystal, salt-cocrystal, and ionic-cocrystal, which have attracted much attention in recent years. In addition, understanding intermolecular interactions and their energetics is important to understand pharmaceutical crystal physicochemical properties such as solubility, stability, tabletability, color, and hygroscopicity, and related topics will also be introduced.

The word ‘crystal’ evokes images of transparent, regular, hard and still solid objects, and this perception goes along with one of the most infamous interpretations of a crystal being a ‘chemical cemetery’ of molecules that was instigated in the very early days of solid-state chemistry. The emerging dynamic and adaptive properties of molecular crystalline materials that were recently amalgamated under the umbrella term ‘crystal adaptronics’, comprise a burgeoning new research direction and one of the most rapidly growing areas in solid-state chemistry, crystal engineering and materials science research. Encouraged by these developments, there is now an increasing number of reports from chemists on unusual mechanical or dynamic properties of molecular crystals. Molecular crystals are not only poised to become the materials of interest not just for future fundamental research, but are also viewed as a new class of light-weight, organic dynamic materials for applications in devices. Concomitant with these exciting developments, there have also been questions and contrasting arguments regarding fundamental aspects of the underlying structural mechanisms. This developing research field is at the stage of maturity where a broader community consensus is necessary regarding fundamental questions such as the mechanisms of deformation of molecular crystals, the role and fate of defects in these processes, and various kinetic/kinematic aspects that are specific to this new class of materials. This microsymposium will focus on the dynamic aspects, and especially the mechanical properties and effects in crystals, aimed at bringing visibility to this research area among crystallographers, whilst also attracting a large cross-section of the materials chemistry community to support the continuing growth of this important research area that lies at the intersection of chemistry, physics and engineering.

Session Chairs: Prof Hideko Koshima and Prof Marijana Djakovic

Bond valence method is a very convenient technique to estimate stability of a specific ion at specific sites or positions in crystal structures. The bond valence method is now applied to several situations, such as structure determination, screening of possible ionic conductors, and investigation of ion migration paths with potential barriers. This microsymposium aims to discuss the current status and future prospects of the bond valence method based on recent research examples. Any research field is welcome.

Session Chairs: Dr Kotaro Fujii and Stephan Adams

The recent progress of neutron sources and diffractometers has made neutron diffraction a practical method, smaller sample size and shorter measurement time, to observe hydrogen atoms and other light elements in chemical crystallography. On the other hand, it is also true that neutron diffraction is not necessarily a familiar technique for many chemical crystallographers. The microsymposium offers a platform to demonstrate the role of the latest neutron diffractometers and analytical methods in understanding the structure and dynamics of light elements in functional organic/inorganic crystals and discussing the potential of neutron diffraction in chemical crystallography.

Co-sponsor: Commission on Neutron Scattering

Session Chairs: Dr Silvia Capelli and Dr Lorraine Malaspina

Crystals can be modified in a variety of ways after they have formed. Postsynthetic modification can involve chemical reaction, either with additional reagents or within the crystal itself. The reaction of molecules within crystals has long been known to yield products often unattainable through conventional synthetic methods. Recently, combining topochemical reactions with the structure and predictability of framework materials has allowed for not only the synthesis of new chemical products, but also the construction of new frameworks with altered properties. Exchange of crystal components (such as metals of ligands in frameworks) can also take place after crystals have been synthesised. Crystals can also be modified by growth of one crystal onto another, to form crystals within crystals. This microsymposium will explore the methodologies and potential of all forms of postsynthetic modification of crystals to generate interesting or improved properties.

Session Chairs: Dr Tatsuhiro Kojima and Prof Hoi R Moon

Organic semiconductors and organic solar cells as well as light emitting diodes are promising materials for a number of potential applications for example versatile flexible electronics. Crystal engineering, in particular controlling intermolecular interactions and charge transfer are key to this area. The scope of this microsymposium is however not limited to novel organic materials. Classical inorganic materials will be discussed side-by-side with organics.

Session Chairs: Mahesh Hariharan, Panče Naumov

Supramolecular interactions, inclduing hydrogen bonds, halogen bonds, chalcogen bonds and others, are the key tools in the design of molecule-based materials. The understanding and use of such non-covalent interactions is expanding at a rapid rate, through the use of both experimental and computational methodologies. Contributions concerning the nature of intermolecular interactions or the use of such interactions in crystal engineering will be welcome in this microsymposium.

Session Chairs: Prof Valentina Dichiarante and Catharine Esterhysen

Organic-inorganic hybrid materials offer great promise as materials in diverse fields, including optics, energy storage, and magnetic materials. The interaction between the organic and inorganic components of a material can give rise to unique and exciting combinations of properties. This microsymposium will discuss advances in the developmnt and understanding of the structure and properties of organic-inorganic hybrid materials.

Session Chairs: Dr Chris Ritchie and Dr Patrice Kenfack Tsobnang

The remarkable variety of crystal forms found in molecular crystals is an ongoing area of interest. Exploring the structural landscape of materials has improved understanding of the behaviour of molecular crystals, as well as uncovering new and unexpected crystal forms. This microsymposium will focus on the wide variety of techniques and methodologies used to explore crystal landscapes, as well as the understanding and use of different crystal forms in various applications. Contributions addressing topics such as multicomponent crystals (including salts, co-crystals, solvates and combinations of these) and polymorphism will be welcome.

Session Chairs: Vincent Smith and A/Prof Hidehiro Uekusa

Mechanochemistry is the use of mechanical energy to affect chemical reactivity. It is an increasingly powerful and versatile tool for both chemical and crystal synthesis. This microsymposium will explore recent advances in the use and understanding of mechanochemistry in producing or adapting crystalline materials.

Session Chairs: A/Prof Ranjit Thakuria and Prof Hajime Ito

As crystallographers, we are lucky to have access to a number of information databases, as well as powerful tools to extract useful data from these collections. This microsymposium will present advances in the tools to explore crystallographic databases, as well as recent reserach utilising databases to advance understanding of the behaviour and properties of crystals.

Session Chairs: Dr Samuel Tetteh and Miss Suzanna Ward

Crystals can interact with external stimuli in a multitude of interesting ways. Some crystals respond to external stimuli, such as light, heat, electric or magnetic fields, or external stress, to cause structural and physicochemical property changes. Such property switching can include aspects such as crystal color, emission properties, outer shape, dielectric properties, etc., which are triggered by crystal structure change. Stimuli-responsive crystals are attractive as a new knowledge source for fundamental science and practical applications. This microsymposium will focus on the latest research on stimuli-responsive soft crystals affording various physicochemical property switching. It will also include aspects such as photochemical reactions in crystals and the study of excited states using diffraction experiments.

Session Chairs: A/Prof Yumi Yakiyama and Prof Kana M. Sureshan

This microsymposium will focus on efforts to make crystallography a more inclusive and diverse science. Contributions addressing topics such as crystallography in the developing world, gender in crystallography and attracting young people to careers in STEM will be welcome.

Co-sponsor: Gender Equity and Diversity Committee, Commission on Crystallographic Teaching

Session Chairs: Prof Maria Cristina Nonato and Dr Alison Edward

Porous materials can be tailored to achieve desired structures and properties by designing building block molecules, allowing for the development of functional porous materials adaptable for various applications. This micro-symposium focuses on both structural and functional aspects of molecule-based crystalline porous materials constructed through coordination bonds, covalent bonds, hydrogen bonds, charge-assisted hydrogen bonds, pi-stacking interactions, van der Waals interactions and other supramolecular interactions. Unique design strategies, topological and geometrical features, and structure-property relationships of porous materials will be discussed. In parallel, the wide range of functionalities of these materials, such as selective sorption and separation of certain gases and chemicals, photo- and electro-luminescence, charge-conductivity, catalytic properties, stimuli-responsiveness, and others, will be discussed.

Session Chairs: Prof Ichiro Hisaki and Sareeya Bureekaew

X-ray ptychography has been established as a high-quality microscopy technique with a spatial resolution that can be better than 10 nm. Its performance is directly related to the quality of the coherent diffraction measurement. Consequently, diffraction-limited storage rings promising several orders of magnitude increase in coherent flux will push the development of X-ray ptychography towards higher resolution and throughput. Improvements in instrumentation, data acquisition and image reconstruction will be needed to deliver the next generation of enhancements in spatial and time resolution. This micro-symposium will bring scientists together to discuss applications of X-ptychography and to define its future developments.

Session Chairs: Ana Diaz and Cameron M. Kewish

Data and analysis are more and more important in synchrotron radiation and XFEL community, which is in accord with other scientific disciplines. Recently, many facilities are offering data service as a critical part of the facility capability. This microsymposium will provide an overview of the current status and future outlook from the viewpoint of X-ray science.

Co-sponsor: Commission on Crystal Growth and Characterization of Materials

Session Chairs: Nicholas Schwarz

X-ray free-electron laser (XFEL) serial femtosecond crystallography (SFX) has enabled high-resolution structure determination from tiny microcrystals at room temperature, while outrunning structure-altering radiation damage. This has facilitated room temperature structure determination from very small microcrystals of hard-to-crystallise, radiation-sensitive targets, G protein-coupled receptors, as well as in vivo grown nano/microcrystals. The use of tiny microcrystals at room temperature permits rapid reaction initiation and allows the macromolecule to retain functionally relevant conformational flexibility, which may be disrupted by cryopreservation. The development of time-resolved SFX has made use of this for structural investigations of reaction dynamics with unprecedented temporal resolution in numerous systems and with multiple reaction initiation mechanisms.

Meanwhile, microfocus beamlines at modern synchrotrons, coupled with fast frame-rate detectors and automated microcrystal sample delivery systems, are pushing the capabilities of synchrotron macromolecular crystallography to ever-smaller crystals and faster data collection. Serial snapshot crystallography at synchrotrons maximally spreads the radiation dose over many crystals, narrowing the gap between XFEL and synchrotron capabilities for room temperature microcrystallography.

This microsymposium will present results from the state-of-the-art in time-resolved serial crystallography at XFELs and synchrotron sources, while highlighting the enabling technologies involved. Talks are welcome covering recent high impact applications and technique development, including serial crystallography data analysis, microcrystal sample delivery and reaction initiation..

Session Chairs: Dr Dominik Oberthür

The natural occurrences of crystal growth in living organisms and cells (so-called in vivo crystallography) are phenomena known for over a century. Initially considered as rare incidents, these events are now recognised as widespread and present in all kingdoms of life. They may result in harmful physiological responses but, more often than not, have evolved functional roles ranging from energy storage and viral persistence to self-defense mechanisms. There are promises that mastering these complex events could facilitate the structural analysis of macromolecules in their native forms and directly from their natural environment.

Various pipelines toward in vivo crystallography have been implemented in recent years as part of national and international projects in France, Germany, Australia, Japan and the USA. These platforms represent examples of integrated solutions as an alternative to classical structure determination methods. Direct access to state-of-the-art instruments available on synchrotron sites will prove to be a key element for the success of these platforms, as a complete integration of multiple techniques is mandatory to fully pin down these events. The full spectrum of synchrotron radiation light has been used for the characterization of the events behind naturally occurring crystal growth, and notably cryo transmission soft x-ray microscopy, VUV-Vis microscopy, IR microscopy, small-angle x-ray scattering, and x-ray diffraction. X-ray free electron laser facilities and micro electron diffraction also provide powerful tools to solve the 3D-crystal structures of the most challenging in vivo-grown crystals.

During the (proposed) symposium on 'in vivo crystallography and synchrotron radiation', we would like to bring together representatives who develop instrumentations and methodologies required for the characterization of these events as well as those who applied them to relevant biological systems. The symposium would provide an opportunity to emphasize the importance of an integrated approach at synchrotron facilities in order to fully comprehend and utilise the secrets behind in vivo crystallography.

Session Chairs: Prof Leo Chavas and Prof Fasseli Coulibaly

Metals play important and diverse roles in many biological systems and the emerging accessibility of a variety of instruments at synchrotrons worldwide facilitates new insights into their chemistry and interactions. A wide range of systems are being tackled using X-ray absorption spectroscopy (XAS) focusing on the study of trace metals found in proteins involved in human diseases (e.g. neurodegeneration), plant biochemistry and toxic waste. XAS permits structure determination of solvated species under conditions relevant to their function as there is no requirement for crystalline samples. This is particularly important for metalloprotein species where polypeptides folding, or acid/base reactions of the sidechains can impact on the active site structure often associated with a metal. Also, investigations of exogenous ligands and metallopharmaceuticals require native conditions to modulate protein properties. Consequently, biological systems create the most challenging problems for XAS, not least due to the impact of unwanted photoredox chemistry which is particularly pronounced for solution samples at ambient temperatures. These problems have been addressed by various techniques including rapid freezing of solution, employing solution jets and X-ray free-electron laser, methods of continuous flow of sample solution under potentiostatic redox control. Furthermore, micro and nano imaging probes are used to localise and quantify metals by accessing their local and electronic structures in complex multiphase systems from human tissue to plants and cells. These approaches bridge traditional XAS with imaging techniques such as X-ray Fluorescence (XRF), Scanning Transmission X-ray Microscopy (STXM) and X-ray Computed Tomography (XCT).

Session Chairs: Dr Victor Streltsov

Research on energy related materials, such as those used as catalysts, photovoltaics, electrodes, electrolytes and adsorbents is a priority in the material research community. X-ray and neutron techniques such diffraction, total scattering and X-ray absorption spectroscopy (XAS) provide information on both average and local atomic structure, electronic structure and how they effect performance. This MS aims to highlighting recent results using XAS, diffraction and total scattering in the field of energy materials, highlighting their complementarity. Work on novel materials and also strategies to improve their performance through in-situ and operando studies are encouraged.

Co-sponsor: Commission on Powder Diffraction

Session Chairs: Dr Giuliana Aquilanti and Dr Aline Ribeiro Passos

Around the world, new and upgraded synchrotron radiation sources push towards extremely low emittance and diffraction limited X-ray beams. The first of these sources are already in operation (such as MAX IV in Sweden, Sirius in Brazil, ESRF in France). Other facilities are preparing upgrades and are eager to learn from the experiences made at already operating 4th generation sources. Classical X-ray absorption fine structure spectroscopy (XAFS) is applied routinely in many areas of physical and chemical sciences. It became essential for explaining structure-activity relationships of many materials. XAFS is also complemented by a whole bunch of related spectroscopic methods like resonant and non-resonant emission spectroscopy. This micro symposium aims to give an overview of fascinating new opportunities in X-ray spectroscopy opened up by 4th generation sources and discuss the experimental challenges to continue the use of classical XAFS spectroscopy as an analytical method. Faster measurements for time-resolved studies will allow to monitor dynamic systems with unprecedented accuracy. Micro-XAFS and related spectroscopic methods, that use small beams to achieve high spatial resolution, will benefit from the huge improvement of brilliance. The high degree of coherence of the photon beam will enable the routine use of new imaging methods like XAFS-ptychography that will provide 2D/3D chemical information with nanometric resolution. Finally, XAFS and the new X-ray spectro-imaging methodologies providing higher sensitivity to various chemical and physical properties require advanced data analysis strategies and synergic integration with multi-technique laboratory characterisations.

Co-sponsor: Commission on Synchrotron and XFEL Radiation

Session Chairs: Dr Edmund Welter and Amelie Rochet

Today, access to high-brilliance X-ray radiation and fast-paced developments in methodology and instrumentation (e.g., high- resolution detectors) makes it possible for researchers to acquire high-quality X-ray spectra in operando, follow ultrafast excited-state dynamics far from equilibrium, observe stochastic events, and record single-shot X-ray spectra of beam-sensitive samples by exploiting the ultrashort and ultrabright X- ray pulses generated at XFELs. However, the high resolution of modern X-ray spectra, coupled with ever-increasing data acquisition rates, has brought acutely into focus the challenge of efficient and accurate analysis of these data to reveal the rich information encoded therein.

To address this challenge, it is becoming increasingly clear that the use of artificial intelligence and machine learning (AI/ML) – used as an umbrella term for a variety of statistical algorithms that build predictive, or decision capable models based on inferences from data – is vital. From forward prediction to classification, decomposition, and inversion, AI/ML is enabling new capabilities from real-time information extraction to autonomous experimentation. This microsymposium is focused upon discussing the recent process of AI/ML methods for X-ray Spectroscopy and Scattering and highlighting how they are being increasingly integrated into the typical workflow of experiments from conception through to analysis. It will focus on problems that challenge traditional analysis approaches but are addressable through machine learning, including leveraging the knowledge of simple materials to model more complicated systems, learning with limited data or incomplete labels, identifying meaningful spectra and materials representations, mitigating spectral noise, and others.

Session Chairs: Thomas Penfold and Maria K. Chan

The optimization of energy technologies is a grand science and technology challenge facing us today. Meeting this challenge requires resolving fundamental mechanism underlying energy conversion/conserving processes. Tracking electronic and structural evolution over short time scale from femtoseconds to microseconds is technologically challenging. Laser-pump, X-ray probe, time-resolved X-ray spectroscopy techniques (including XAS, XES and RIXS) are powerful characterization tools in this regard. In recent years, there have been tremendous advancements of time-resolved X-ray spectroscopy techniques at both free electron laser and synchrotron light sources, which have opened doors to new, exciting time-resolved science opportunities. The applications of ultrafast X-ray spectroscopy have been expanded from the study of relatively simple model systems to complex processes/reactions with multiple reaction channels and mixtures of intermediate species in-situ/operando. This Micro Symposium will bring together world experts to present the recent advances in X-ray spectroscopic techniques and their applications in the field of energy conversion.

Co-sponsor: Commission on Synchrotron and XFEL Radiation

Session Chairs: Prof Federico Boscherini and Dr Xiaoyi Zhang

We have seen an extraordinary plethora of complementary methods of x-ray techniques with applied pressure developed in the last few decades, as well as a recent advent of the fourth generation synchrotron sources around the world. This is renewing interest and opportunities of research in materials under extreme conditions with diverse methods such as X-ray absorption spectroscopy, X-ray diffraction, X-ray Raman Scattering, X-ray Emission Spectroscopy, Nuclear Forward Scattering among other x-ray techniques under extremes. Examples of this are the newly available nano-polycrystalline diamond anvils that allow glitch-free x-ray absorption spectra to be taken at a great variety of energy scanning beamlines. This includes micrometer and nanometer focused beam size available at recent beamlines worldwide that allow very good conditions to reach extremes pressures with very small diamond culets. This has been done recently with either toroidal shaped anvils or double-stage anvils, which both amplify the force applied in a very small area to reach pressures as high as 1 TPa in diamond anvil cells.

This microsymposium aims at covering several of the advances and opportunities combining x-ray spectroscopy and scattering methods under pressure and other extreme thermodynamical conditions to fields as diverse as condensed matter, chemistry, material synthesis, soft matter and geosciences.

Co-sponsor: Commission on High Pressure, Commission on Powder Diffraction

Session Chairs: Monica Amboage and Dr Narcizo M. Souza Neto

The foundation of experimental science is data and the progress of science relies upon a study being reproducible by others’ analysis of the same data (quote from: The vital role of primary experimental data for ensuring trust in Photon & Neutron) science, A. Götz et al., https://doi.org/10.5281/zenodo.5155882 ). Open Science policies requires that no research data should be lost but should be made available to the research community according to the FAIR principles. Raw data sets are now becoming more and more available in discipline specific archives as well as general repositories such as Zenodo. Raw data are also increasingly linked to databases such as the Cambridge Structural Database (CSD)or the Protein Data Bank (PDB). They can be retrieved by other scientists for purposes such as reanalysis by newer methods or protocols and for software and methods development and they are important for validating the interpretation of structural features. This microsymposium aims at discussing the state-of-the-art in data re-use, its successes, and problems.

Session Chairs: Dr Loes Kroon-Batenburg and Dr James Hester

This session titled, “The interoperability of crystallographic data and databases” aims to explore the manner in which crystallographic data can be appropriately applied across disciplines to enable the advancement of science. Interdisciplinary research requires a common crystallographic language, an ability to unambiguously understand the crystallographic information, and data interoperability – the property that allows for the reliable sharing of resources or data between different systems. In an age of data-driven science, these attributes are required for processing of data by machines as well as people.

Session Chairs: Dr Ian Bruno and Prof John Helliwell

Session Chairs: Dr Hanna Dabkowska and Prof Santiago Garcia-Granda