Reports on the 25th IUCr Congress


When the Czech and Slovak Crystallographic Association (CSCA) won its bid, at the 23rd IUCr General Assembly in Montreal in 2014, to hold the 25th anniversary IUCr Congress and General Assembly in Prague in 2020, it had no conception of the huge challenges that lay ahead. Nevertheless, the organizers triumphed and produced an excellent hybrid event in 2021 that is being hailed as the beginning of a new era. A round-up of the Congress by the Chair is published below, followed by a number of reports from Plenary Lecture and Session Chairs.

A hybrid Congress in a time of pandemic, August 2021

Radomír Kužel, IUCr25 Chair

After all, the Congress was realized basically as planned in the last few months as a hybrid event and in a very enjoyable atmosphere for both on-site and online participants, as attested by the emails received after the congress (see below). The possibility for online presentation was a very positive aspect because for invited speakers this can be quite simple and much cheaper. Only a few approached speakers declined the invitation. There were more than 2500 pre-registered people and the total number of final registrations reached nearly 1700. Because of travel restrictions, less than one third of those registered were able to travel to Prague; most of these were from Poland and Germany although others arrived from France, Spain, Sweden, Denmark, Finland, Croatia, Italy, USA and other countries.

[Group photo]


The high-quality programme consisted of 3 plenary lectures, 5 lectures connected with prizes, 35 keynote lectures, 103 standard sessions, 7 special sessions, a Software Fayre – always 9 sessions in parallel, 55 poster sessions and several commercial presentations. In total 624 lectures and over 550 posters in different forms were presented at the Congress.

Significantly, two sessions were devoted to the structural biology of coronaviruses and to new methods to fight the pandemic. In biocrystallography, the highest number of abstracts were submitted to the sessions on structural biology of enzymes and bioinformatics. The new W. H. and W. L. Bragg Prize Lectures were also related to biocrystallography – Structure-guided design of next-generation malaria vaccine (Jean-Philippe Julien, Canada) and Targeting COVID-19 Viral Enzymes in an Evolving Landscape of Publishing and Peer Review (James Fraser, USA) – as well as the plenary lecture by David Eisenberg: The structural biology of pathogenic amyloid fibrils, which are associated with many degenerative diseases such as Alzheimer's.

[Bragg Prize]
The Ewald Prize Lecture and one plenary lecture were related to crystallographic data and databases, the Ewald Prize having been awarded to Olga Kennard (UK) for the development of the Cambridge Structural Database, and the Plenary Lecture by Helen Berman (USA) describing the history of the growth of the Protein Data Bank. Several sessions and the pre-Congress school were devoted to electron crystallography (structural studies by electron diffraction). The school, which had nearly 200 registered participants, was mostly online but the last day was in the hybrid format. In this branch, the Gjønnes Medals were awarded to Sven Hovmöller (Sweden) and Ute Kolb (Germany). Another significant topic of the Congress was quantum crystallography. For both of the above topics, a relatively large number of experts were able to attend in person. Among materials, those attracting the most attention were materials for energy conversion and storage often studied in situ (also the subject of Clare Grey's plenary lecture: In situ and ex situ studies of battery materials with magnetic resonance and diffraction methods), nanomaterials and magnetic materials. The highest number of abstracts were in the sessions "Complex structure of minerals and inorganic compounds" and "Phase transitions in complex materials". There was also much interest in the session on disordered materials. Despite there being little publicity about the Congress among chemical crystallographers, the highest number of registered people was from this area – materials important for pharmaceutical industry, metal–organic frameworks (MOFs) and catalysis. Two sessions were dedicated to the application of crystallography in art, and many sessions to individual techniques such as neutron scattering, small-angle scattering, synchrotron radiation, XAFS etc.

All the congress materials – recordings of all lectures, posters and other recordings (meetings, concerts) are available for viewing by registered participants till the end of November 2021 (,

All responses of local and remote participants show that the congress was successful in most aspects and better than expected considering that a number of people were sceptical about the hybrid format. Perhaps, it can be taken as an example for future hybrid congresses. Credit should be given to all people involved in the organization. For the good impression of online participants, probably the greatest credit goes to T.R.I., their gCon presentation system and their very professional approach. We were also very satisfied with the Conftool registration system.

The relatively long absence of real events was reflected in a positive acceptance by the onsite participants, the work of the staff of the Prague Congress Center and the catering company, Zátiší. All were doing their best for the success of the conference. Of course, the organizers should be mentioned first: colleagues from the Faculty of Mathematics and Physics - Milan Dopita and other colleagues and students; people from the Institute of Organic Chemistry and Biochemistry CAS (Pavlína Řezáčová, chair of the Local Organizing Committee); Faculty of Science, University of South Bohemia in České Budějovice (Ivana Kutá Smatanová, chair of the International Programme Committee); from the Institute of Biotechnology (CAS); and a very important group, Auletris (headed by Martin Haloun).

In addition to the scientific programme, a social programme was organized – boat trips on the Vltava river, the conference dinner with a Brand New Band concert in National House and a train trip to Pilsen brewery. For more see

Different conference statistics are available at


Dear Radek Well now! The organization of the Congress was fantastic and everything including the remote presentations and interactions were perfect. I congratulate you and your team in achieving the seemingly impossible. This Congress will surely go down in everyone’s memory as a very special success. I am lost in admiration for what you have been able to do. Kind regards Mike

Dear Radek, Pavlina, Ivana, and all Czech Friends, What you have done with the 2020/21 IUCr Congress organization is beyond description. I am writing to express my highest appreciation and congratulations to you and your teams: you have overcome the impossible and organized an amazingly successful IUCr Congress. The organization was flawless but also the scientific content was magnificent. From my point of view (a very active on-line participant) everything worked perfectly; and the quality of the virtual environment was breathtaking. A quantum leap in the mastery of IUCr congress organization. With my all best wishes, Mariusz

Dear Radek, Please allow me to heartily congratulate you and also your team for the organization of the wonderful IUCr Congress. You did an excellent job and organized a great conference. As an on-line attendee I could fully enjoy the meeting. It is a huge advantage that the lectures will be available on-line for three more months. As you said in your closing remark, it is the start of a new era. I believe that the in-person meetings are very important but from now on hybrid conferences and archiving the conference events are recognized and will be followed. I both liked the lecturer and the chair functions of the gCon platform. The poster session was the best I have ever experienced. All best wishes, Petra

Dear Radek, the congress is almost at the end. Since I will not be able to do this in person, let me send you my biggest and warmest congratulations for what you have achieved, it has been a splendid congress with an excellent program and a perfect organization. You and your colleagues have been fantastic. Thank you so much for allowing us to gather in this novel mode, but with really common and joint spirits. Alessia

Dear Radek and Ivana, I had to leave the Congress early to join my family for a vacation. I just wanted to let you know that I think you have done a fantastic job organizing the Congress, especially under these difficult circumstances. Everything was great at all levels of organization, and I think the scientific quality of the meeting was very high. I have heard similar opinions from many other people. I think the Congress was definitely a success. Thank you for all your work! With best wishes, Marcin

Dear Radek, Ivana, Pavlina, and Martin, Congratulations on successfully hosting such a wonderful congress. None could have managed the COVID situation better than you did. The content was top quality, and the opportunities to connect with colleagues were many. I spent the whole morning today working through continuing research-related email conversations started during the congress. I’ll still look forward to watching recordings of some presentations that I missed. Your hybrid meeting platform will be a benchmark for future congresses. Thank you for so many years of effort to strengthen the union and to make Prague 2020 a great experience. I wish you a speedy recovery from the long weeks of fatigue! Branton

Dear Radek, I would like to thank you and all the organizers for an unforgettable congress. Every IUCr congress stays in my mind as an inspiring and engaging experience from a scientific point of view. This time I would say that, looking at you and at your team, I learned from your example how it is possible to face unpredictable events and challenge them by exploring new paths without losing your smile and kindness. As a chair of a session I would like to acknowledge your support in all the phases of the difficult task of assembling the program and the support of the technical team during the session. This IUCr congress was a remarkable event for me as a scientist and more important as a human being. I enjoyed every moment! Grazie di cuore. Consiglia

Dear Radek, It was an amazing Congress and the job you and your teams (all of them) did is unprecedented! We all enjoyed the Prague Congress even though we were not there. You proved that it is possible to "do" a big, hybrid meeting, many others before you tried and failed. You, "The Prague", showed a new way. Frankly I prefer old way - but this IS the way of the future. Hanna


Plenary Lecture 1: The data universe of structural biology

Speaker: Helen Berman

Chair: John Helliwell

[Helen Berman PL1]There are just three Plenary Lectures at an IUCr Congress. At IUCr25 one of these was delivered by Dr Helen Berman on the Protein Data Bank (PDB). We highlight this slide of Helen which so neatly captures all the decades of the PDB including the diversity of the curated structures, technology developments and the very active community involvement in the PDB.

Dr Helen Berman delivered one of the three Plenary Lectures. Helen’s career commenced at the University of Pittsburgh, USA, where she received her PhD under the supervision of George Jeffrey in 1969. Helen moved to the Institute for Cancer Research in Philadelphia, where she began her studies of nucleic acid complexes with carcinogens and drugs. She continued her research in nucleic acid interactions at Rutgers University, where her interests in computing and databases led to her work as Director of the Nucleic Acid Database and as Director of the Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank (PDB). Helen was there at the inception of the PDB in 1971 at the Cold Spring Harbor Conference on Quantitative Biology Symposium on the “Structure and Function of Proteins at the Three-Dimensional Level”, which she described in her Lecture, and onwards to the present day. Under her leadership the scientific and educational mission of the PDB has greatly expanded. This included working with film producers in Hollywood on programmes to explain medical themes such as HIV. Helen has been recognized with many awards, notably the 2006 Buerger Award from the ACA and the 2012 Carl Brändén Award from the Protein Society. As Chair of Helen Berman’s Plenary Lecture at IUCr25 I concluded the Plenary session by offering a vote of thanks to Helen and all involved in making the PDB what it is today, a fantastic resource.


Plenary Lecture 2: In situ and ex situ studies of battery materials with magnetic resonance and diffraction methods

Speaker: Clare Grey

Chair: Jürgen Senker

[Clare Grey PL2]

Clare Grey started her academic career in Oxford, UK, in the group of Tony Cheetham. After receiving her PhD in 1991, she first joined the Veeman group in Nijmegen as Royal Society Post-doctoral Fellow and then DuPont as a visiting scientist. From 1994 onwards, she worked as Assistant, Associate and Full Professor in Chemistry at the State University of New York. Since 2009 she is Geoffrey Moorhouse Gibson Professor in Materials Chemistry at the University of Cambridge and Adjunct Professor at Stony Brook. Clare is one of the leading experts on in-situ and operando studies of modern battery materials with diffraction and solid-state NMR spectroscopic methods. Clare presented a thrilling and lively lecture, summarizing the current state of the art while simultaneously highlighting ongoing challenges. By focusing on lithium-ion batteries, she could stress the impact such studies have on our daily life. With illustrative examples of her research, she pointed out pros and cons of various cathode and anode materials, explained the conundrum of stable LiCoO2-type MMM phases using high nickel content and demonstrated how to follow charging and discharging cycles of batteries in situ. In particular, her studies offer unique insight into the complexity of chemical reactions at the electrodes, including the continuous growth, dissolution and segregation phenomena of intermediate solid phases. By covering also materials for sodium-ion batteries, she introduced the controversial discussion about next-generation batteries, desired to be able to replace the less abundant lithium.


Plenary Lecture 3: The structural biology of pathogenic amyloid fibrils

Speaker: David Eisenberg

Chair: Lars Redecke 

[Eisenberg PL3]

David Eisenberg (UCLA, USA) presented the current knowledge of the structure and stability of pathogenic and functional amyloids, complemented by promising results in structure-based aggregation inhibitor design. Amyloid fibrils are assumed to be the causation of several diseases, including many of the most prevalent degenerative disorders. More than 80 small segment structures from 20 amyloid-forming proteins revealed common features of pathogenic amyloid structures: two or more protofilaments are twisted around each other, each protofilament is a stack of identical bent protein arches from beta-sheets, representing 2D structures that interact via energetically highly stabilized homotypic steric zippers, while highly polarized backbone H-bonds connect the layers. Although polymorphs of identical sequences are common, preferred polymorphs are usually isolated from diseased brains, since a specific polymorph might cause the disease, or is formed by the disease condition. Atomic level insights into fibril structures enabled the design of peptidic inhibitors that bind the growing fibril as a cap, preventing the addition of new strands, as confirmed by using seed-containing brain extracts and biosensor cells producing fluorescence-labelled tau protein. But labile amyloid-like fibrils are also formed by a large number of non-pathogenic proteins containing low-complexity amyloid-like reversible kinked segments (LARKS). LARKS may represent adhesive segments in functional fibrils, which are less stable compared to pathogenic fibrils, and mostly monomorphic. However, mutation can transform functional amyloids into pathogenic amyloids. 


MS-7: High throughput vs. careful planning: How to get the best data?

Chairs: John Helliwell and Selina Storm

In times of highly brilliant beamlines and fast detectors, data collections only take seconds – but what is the way to get the best data? Aina Cohen presented SSRL’s efforts to enable more specialized experiments such as experiments at room temperature, controlled dehydration experiments or light-triggered experiments remotely, making specialized experiments possible in times of crises. Danny Axford, senior beamline scientist at Diamond’s beamline I24, exploits their brilliant microfocus beam in multiple crystal approaches and serial crystallography, pushing the limits of fast data collections and highest quality data. Peter Zwart from LBNL demonstrated that the use of Gaussian process regression in high-throughput infrared spectromicroscopy reduces the amount of measurements and significantly speeds up the measurements. Marcus Müller (Dectris, Switzerland) first remembered his colleague Andreas Förster, who was a highly valued member of the community and who had sadly passed away in May 2021. Marcus then presented the best strategies of collecting data with hybrid photon counting detectors, ranging from fine slicing to strategies for phasing strategies at room temperature. In the next talk, Amy Thompson (University of Queensland, Australia) introduced her approach of automatic analysis for elastically flexible crystals called CX-ASAP, reducing the processing time significantly. Martin Malý from the Czech Technical University then reported a new approach to assess the optimal resolution cut-off with PAIREF.

[MS-7]Screenshot taken during MS-7, contributed by Samar Hasnain, which encapsulates the unique nature of the Congress. The four people in action are taking part from different places; only one is in the live, socially distanced, audience.

Can we answer the question whether the best data are obtained via high throughput or careful planning? As the late and great Michael Rossmann indicated, it all depends on the challenge you are facing. For his pioneering work with highly radiation sensitive virus crystals there is but one option: “shoot first and ask questions later” (Rossmann & Erickson, 1983). Since that time, the development of incredible detector and beamline capabilities has expanded the possibility to the researcher to ‘just open the shutter’. Furthermore, the huge amount of data that can be obtained within a short time creates new challenges, which require new solutions such as those presented in this session.

How to get the best data depends on what your objectives for your measurements are, which should certainly be carefully planned. This is a similar overall conclusion to the individual conclusions of the speakers in this session spanning a quite vast array of topics. 


Rossmann, M. G. & Erickson, J. W. (1983). J. Appl. Cryst. 16, 629–636.


MS-8: Social media and new frontiers for spreading crystallographic information

Chairs: Andrea Ienco and Helen Maynard-Casely

The aim of this microsymposium was to hear how social media and other tools are being used to communicate crystallographic research. After the massive efforts of the International Year of Crystallography in 2014, how has the science communication landscape for crystallographic ideas changed? The session had two invited speakers, Delphine Chenevier (European Synchrotron Radiation Facility, France) and Rhiannon Morris (Walter and Eliza Hall Institute, Australia). Delphine highlighted the importance of a strategy for approaching social media, and how important it is for science to show its human face – The 'Humans of ESRF' project is a fantastic example of that.[1] Rhiannon, who has a large following across social media where she talks about her research and structural biology at large, emphasised that there are many ways to use social media, and broke it down into four types of use illustrating this with numerous examples.[2]

Following on from our invited speakers, we had four contributed talks. Ilaria Gimondi (Cambridge Crystallographic Data Centre, UK) presented on how they are using social media to promote the (now one million) structures in the Cambridge Structural Database to a wide range of users (from kids to researchers [3]) – including their successful hashtags #FeatureStructureFriday and #TopTipsTuesdays (also those attending #IUCr25 check out the #CSDLeaderboard). Sneh Patel (University of Auckland, New Zealand) talked us through how memes can be really flexible to convey complex science ideas and foster cohesion in many different groups.[4] Elizabeth H. Driscoll (University of Birmingham, UK) presented the awesome tactile Battery Jenga project and discussed how to make social media and science outreach accessible to all.[5] Paolo Mazzeo (University of Parma, Italy) illustrated how important social media has been as a tool for the Young Crystallographers of Italy group, especially in COVID times, including a series of interviews with crystallographers on YouTube.[6] He also introduced a very exciting new comic-book project.

The session was enjoyed by 30 viewers online, as well as a capacity crowd at the conference centre in Prague. The wide range of topics and perspectives shared by the speakers, communication experts as well as researchers engaged in science communication, very much showed how important sessions like this are for sharing ideas to make crystallography as relevant as we can.



[2] You can follow Rhiannon on Twitter @Scientist_Rhi and on Instagram @scientist_rhi


[4] Inorganic Memes for C2v Teens; X-ray Crystallography maymays

[5] Driscoll, E. H., Hayward, E. C., Patchett, R., Anderson, P. A. & Slater, P. R. (2020). J. Chem. Educ. 97, 2231–2237; Lithium Shuffle (accessed January 2021)

[6] Young Crystallographers of Italy YouTube Channel

[MS-8]Left: a crystallographic meme. Centre: Battery Jenga and the Lithium Shuffle. Right: the comic-book project.


MS-74: Structural biology of receptors, signaling and membrane proteins

Chairs: Susan Buchanan and Michael Parker

We were honored to co-chair a microsymposium on transmembrane signaling, a very active area of structural biology research that, despite years of studies and a few Nobel Prizes along the way, still has many mysteries to explore and puzzles to solve. We were fortunate to attract leading speakers from four continents which presented its own challenge with a virtual meeting. Although the session was said to start at 10.20 am in Prague, for the co-chairs it was starting at 6.20 pm for one of us and 4.20 am for the other!

The session was led off by Isabel Moraes (National Physical Laboratory, UK) who described her structural work on the archaerhodopsin-3 transporter with crystal structures resolved to 1.1 Å resolution, quite an achievement for a membrane protein. The high resolution highlighted how minimal displacements of charged and polar groups within the low dielectric environment of the membrane can induce changes in the chromophore conformation. Our next speaker was Robert Keenan (University of Chicago, USA) who described his cryoEM work on a ~360 kDa ribosome-associated complex comprising the core Sec61 channel and five accessory factors which revealed a large assembly at the ribosome exit tunnel organized around a central membrane cavity. Oksana Degtjarik (Weizmann Institute of Science, Israel) gave a fascinating talk on the cryoEM structure of the melanocortin receptor 4, a G protein-coupled receptor that plays a key role in regulation of food consumption and energy expenditure, bound to an agonist recently approved for the treatment of obesity. Michael Healy (University of Queensland, Australia), presented crystal structures of components of the Commander complex, an ancient and conserved regulator of intracellular trafficking. Bronte Johnstone (University of Melbourne, Australia) described the crystal structures of a bicomponent pore-forming toxin from a bacterium that lives in the midgut of mosquitoes. The session was rounded off with a talk from William Bourguet (Center for Structural Biology – Montpellier, France), who described his studies on the retinoid X receptor/pregnane X receptor heterodimer, which plays an essential role in controlling xenobiotic responses, which revealed its binding promiscuity and ability to accommodate bipartite ligands. We thank all the speakers for very stimulating talks which highlighted the full gamut of structural tools that can be deployed to answer key biological and medical questions.



MS-96: Crystallography schools to promote interdisciplinarity in science

Chairs: Alice Brink and Serena Chiara Tarantino

This microsymposium described a vibrant and lively crystallographic community, actively and tirelessly engaged in a plethora of educational and outreach initiatives. The intention is to support the growth of researchers and provide tools to allow crystallographers to meet the demands of interdisciplinary challenges within the future scientific research fields and to strengthen the unifying role of crystallography. Our speakers came from diverse backgrounds across the globe and presented many initiatives, which promotes interdisciplinarity.

[MS-96]Group photo of MS-96 chairs and speakers taken in the Congress Virtual Foyer. Marielle Agbahoungbata and Dubravka Sisak do not appear in the photo.

D. G. Lamas (Argentina) described several education and outreach activities carried out throughout Latin America in the past year. He highlighted how the intrinsic interdisciplinary character of these activities enriched all participants. M. Y. Agbahoungbata (Benin) described the X-TechLab, a regional crystallographic research and training platform, the result of the interaction between the Lightsources for Africa, the Americas, Asia, Middle East and Pacific (LAAAMP) and the Sèmè City hub, one of Benin Government’s flagship projects, which aims to create a world-class knowledge and innovation centre in Africa. D. Sisak (Switzerland) gave a talk on how the use of social media, industry–academia collaborations, and online interaction tools in both real and virtual schools can contribute to build and maintain crystallographic communities. L. Suescun (Uruguay) gave a personal 10-year perspective on teaching in crystallography schools in Latin America and shared some of the strategies he developed to improve understanding of symmetry in a class of students coming from different backgrounds. L. Dawe (Canada) described their methods to develop high impact crystallography skills through local undergraduate curricula and the presentation of regional workshops and schools, with particular reference to experiences in the ACA region. S. Ward (UK) highlighted efforts made by CCDC to cultivate more interdisciplinarity in science and engage scientists across research areas and ages through their involvement in a variety of schools, workshops and science festivals globally and by the creation of more virtual resources. 

21 September 2021

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