Women in Crystallography fundraising project – first awardees announced

The “Women in Crystallography” project, an initiative of the ECA General Interest Group on Education in Crystallography (GIG-03), aims to improve the participation of women, especially young scientists, at events around the world and to create a balanced attendance among participants and speakers.

Funds are raised via donations for limited-edition T shirts, first seen at the launch of the project at ECM31 in Oviedo, Spain in 2018, and then making an appearance at ECM33 in Versailles, France in 2022; down under at the IUCr Congress in Melbourne, Australia in 2023; and across the Atlantic at ACA2024 in Denver, CO, USA in 2024. For the history of the logo, see here.

The first awardees are already benefiting from this fund to attend different crystallographic events:

Lamis Elaa Eldin Refat, from Ireland, attended the 15th International Workshop on Crystal Growth of Organic Materials in Phuket, Thailand in July 2024

Anara Omarova, from Kazakhstan, attended the 9th European Crystallography School in Nancy, France in June 2024

Almudena Inchausti Valles, from Spain, took part in the 2nd High-Pressure Single-Crystal X-Ray Diffraction Summer School in Edinburgh, UK in July 2024

Laura Pacoste, from Sweden, will join ECM34 in Padova, Italy in August 2024.

The fundraising for this project will continue at ECM34, where the 2024 edition of the T shirt will be available from the ECA booth as well as those of co-supporters Dectris, the IUCr and STOE. The promoters of the initiative have created the hashtag #Womenincrystallography to share on X (Twitter).

First video in the “Women in Crystallography” series

GIG-03 has also announced the release of the first video of the project supported by the Royal Society of Chemistry Inclusion and Diversity Fund. The project’s scope is to celebrate the importance of women in the field of crystallography and science while raising awareness about the pitfalls and obstacles on the way to reach gender parity in science, eliminate stereotypes, increase sensitivity and facilitate equal treatment of everyone at all stages of a scientific career. The speaker is Professor Shanti Deemyad from the Department of Physics & Astronomy of the University of Utah, Salt Lake City, UT, USA: “Journey Through the Quantum Realm: My Path as a High-Pressure Physicist”.

Watch the video on the ECA YouTube channel here. 

Dieter passed away at the hospital in Lausanne, Switzerland, after a long neurodegenerative decline. He leaves behind his wife, Vera, and his two children, Charlotte and Thomas.

I met Dieter in 1966 when I started my doctoral studies at the Institute of Crystallography at the ETH in Zurich. That was shortly before his departure for a postdoctoral internship in the USA. In 1969 he returned to Zurich, bringing with him the newly developed X-ray System of programs for the solution of crystal structures. I was very fortunate to take advantage of it: it allowed me to crack a difficult structure by direct methods and finalize my PhD thesis. Later, it was also Dieter who helped me to find the most suitable place for a postdoctoral position, in David Templeton’s group in the Lawrence Berkeley laboratory.

The experience gained by Dieter in America, first in Pittsburgh in Professor George Allen Jeffrey’s Department of Crystallography and then at UCLA in Professor Ken Trueblood’s Laboratory, in addition to his PhD with Professor Fritz Laves’ group at the ETH in Zurich, formed an excellent basis for a successful career in crystallography. Indeed, shortly after his return from the USA, in 1970 he was offered a position as a lecturer in the Science Faculty at the University of Lausanne for a basic course in crystallography. Three years later, he was offered the opportunity to create and lead the Institute of Crystallography at the same institution with the position of Extraordinary Professor, which was later upgraded to full Professor in 1978.

My stay in Berkeley was coming to an end when Dieter visited me in 1973 and invited me to complete his team in Lausanne. Thus, in 1974, I returned to Lausanne to pursue my career in crystallography as a lecturer in Dieter’s lab.

Since its creation, the Institute of Crystallography has delivered lectures and practical courses in various fields of crystallography to students of the University of Lausanne (UNIL) and of the Federal School of Technology (EPFL). In particular, students of physics, chemistry, materials and earth sciences have followed the basic and advanced courses. Our common book (Schwarzenbach & Chapuis, 2006) resulted from our experiences in teaching crystallography.

In parallel, the research work of Dieter and his team developed in numerous directions of crystallography. Measuring electron density in crystalline structures using diffraction methods was an important part of Dieter’s interests. Would precise electron densities measured by diffraction be able to reproduce certain physical quantities, such as electric field gradients (EFGs)? One of his most cited articles (Lewis et al., 1982) concerned the charge densities and EFGs in corundum, α-Al₂O₃, where the capabilities and limits of diffraction methods were clearly demonstrated. Other important studies followed, including of the charge densities in cuprite, Cu₂O (Restori & Schwarzenbach, 1986), a paper published with his PhD student Renzo Restori in which the influences of the data-reduction processes, anisotropic displacements and the deformation models were explored. Other compounds like Li₃N, TiO₂, CoS₂ and NiS₂ were all part of an important programme of studies on charge densities.

During his career, Dieter developed some very fruitful collaborations with colleagues from nearby institutions. Hans-Beat Bürgi, head of the Laboratory of Crystallography in Bern, and Howard Flack from the University of Geneva were among them. The discovery of C₆₀ resulted in many interesting studies, both in Bern and Lausanne. The development of the Xtal system of programs by Dieter’s PhD student Eric Blanc contributed greatly to obtaining successful results. His LSLS (‘Lausanne least-squares’) program had some new capabilities regarding absorption, extinction corrections and twinning which led to the C₆₀ paper by Bürgi et al. (1992). This fruitful collaboration on fullerenes resulted in four additional papers on various modifications and phases, improving models and obtaining more precise data on the orientational disorder and C—C bond distances.

Dieter and Howard Flack published an important series of well cited publications relating to some new theoretical developments in the methodologies of crystal diffraction. Both laboratories were involved in the software developments of the XRAY system and its successor, Xtal. About a dozen papers covering various topics from the use of least-squares restraints for origin fixing in polar space groups (Flack & Schwarzenbach, 1988) to the evaluation of transmission factors and their first derivatives with respect to crystal-shape parameters (Blanc et al., 1991) were published. Perhaps the most tangible result of their collaboration was the establishment of the Subcommittee on Statistical Descriptors by the International Union of Crystallography (IUCr). A panel of international specialists in statistical methods in physics and crystallography joined efforts to establish a series of recommendations for the proper treatment of statistical errors in crystallographic research. Dieter was the Chair of the panel, which also included Howard as a member. Two reports, Statistical descriptors in crystallography parts I and II, resulted (Schwarzenbach et al., 1989, 1995). They listed a series of 13 recommendations, the validities of which form the basis of the current statistical treatment of crystallographic data. It is owing to the second report that the commonly used term ‘estimated standard deviations’ (e.s.d.’s) was replaced by the more accurate term ‘standard uncertainties’ (s.u.’s).

While studying the impressive list of Dieter’s scientific publications, close to 150, I was struck by the diversity of his interests, which covered a very large number of fields in crystallography. They extended from historical notices to mathematical crystallography, symmetry, diffraction theories and structure modeling, to cite only the most important topics. Dieter had an excellent memory and he always impressed his audience with his vast knowledge of crystallography.

The IUCr also benefited greatly from Dieter’s expertise, as he served as a Co-editor for both Acta Crystallographica Section A (from 1992 to 2002) and Section B (from 1992 to 1999). He was then appointed as Section Editor for Acta Crystallographica Section A in 2002, a position he held to 2011, and as part of this role he was also an ex officio member of the Commission on Crystallographic Nomenclature.

Under Dieter’s leadership, the Lausanne Institute of Crystallography attracted a large number of international visitors. This was facilitated by two other institutions in Lausanne: the Herbette Foundation from UNIL and the ‘3^e cycle’ of physics (which would now be called a doctoral school) of the French-speaking part of Switzerland. Both institutions were able to support the visit of international lecturers for a few months. During that period, we could greatly benefit from the lectures of a very impressive panel of specialists, including Aloysio Janner, Ted Janssen, David Templeton, Pierre Toledano, Richard Welberry, Terry Willis, Hans Wondratschek and Akiji Yamamoto. The first version of Richard Welberry’s book on X-ray diffuse scattering appeared in Lausanne as lecture notes on the same subject! It was also in Lausanne that Howard Flack developed the concept of his famous parameter during the visit of David Templeton and fruitful discussions on Rodger’s η parameter.

Under Dieter’s direction the Institute of Crystallography led to the creation of the very successful Swiss–Norwegian beamline (SNBL) at the ESRF in Grenoble. In the beginning, the essential problem for Dieter and Hans-Beat Bürgi (who was also interested in this facility) was not the financing of the beamline but rather finding first common objectives between the two participating countries and creating common visions to lead the project. It took a few years to solve all the administrative problems leading to the creation of the SNBL Foundation. Today the SNBL is a flourishing institution for the benefit of Swiss and Norwegian scientists.

Dieter was also admired by members of the Institute for his deep knowledge of the history of Switzerland. He could also cite entire poems from German and English literature, in particular extracts from Goethe’s Faust and quotes from Shakespeare.

Dieter was a fine musician and very athletic. His career as a musician started as a student in 1957 as a violinist in the Zurich Academic Orchestra. He pursued his musical activities in Lausanne long after his retirement and participated actively in a few amateur orchestras, very often along with Vera, who is a respected violist. Dieter also rode his bicycle to the Institute of Crystallography and back home every day, a distance of about 12 km with a significant hill climb. He liked being accompanied by his son on bike rides and sometimes cycled for more than 170 km to tour around Lake Geneva. He was also a real mountaineer and cross-country skier. I had many opportunities to climb several Swiss summits with him, both in summer and winter. I remember very clearly our party of four starting a ski tour from Rothenboden over Zermatt for the ascent of the Pointe Dufour, the highest point in Switzerland (4634 m). By the end of the ascent, only the two crystallographers had managed to reach the summit.

Dieter also joined from the outset a basketball team called OURRS that brought together professors from UNIL and EPFL. Every Tuesday during term time we would meet for an hour of physical exercise and a basketball game. Dieter participated actively in the team activities until his physical abilities started to diminish. Unfortunately, Dieter passed away just a few days before the celebration of the 50th anniversary of the team.

Dieter was not only my mentor but also a dear friend, whom I will miss.

Acknowledgements

The help of Vera Schwarzenbach, Alla Arakcheeva, Eric Blanc and the staff of the IUCr Editorial Office in Chester is acknowledged for providing useful information for writing this article.

References

Blanc, E., Schwarzenbach, D. & Flack, H. D. (1991). J. Appl. Cryst. 24, 1035–1041.

Bürgi, H.-B., Blanc, E., Schwarzenbach, D., Liu, S., Lu, Y., Kappes, M. M. & Ibers, J. A. (1992). Angew. Chem. Int. Ed. Engl. 31, 640–643.

Flack, H. D. & Schwarzenbach, D. (1988). Acta Cryst. A44, 499–506.

Lewis, J., Schwarzenbach, D. & Flack, H. D. (1982). Acta Cryst. A38, 733–739.

Restori, R. & Schwarzenbach, D. (1986). Acta Cryst. B42, 201–208.

Schwarzenbach, D., Abrahams, S. C., Flack, H. D., Gonschorek, W., Hahn, Th., Huml, K., Marsh, R. E., Prince, E., Robertson, B. E., Rollett, J. S. & Wilson, A. J. C. (1989). Acta Cryst. A45, 63–75.

Schwarzenbach, D., Abrahams, S. C., Flack, H. D., Prince, E. & Wilson, A. J. C. (1995). Acta Cryst. A51, 565–569.

Schwarzenbach, D. & Chapuis, G. (2006). Cristallographie. Lausanne: EPFL Press.

This article has been published in Acta Cryst. (2024). A80.

1. Introduction

The aim of this article is to report on the first Senegalese Day of Crystallography organized by the Senegalese Crystallographic Association (ASC, Association Sénégalaise de Cristallographie).

2. Context

The First Senegalese Day of Crystallography (Cristal Ô) organized by the ASC took place on 19 February 2024 at Cheikh Anta DIOP Dakar University in the conference room of the International Center for Research and Training in Applied Genomics and Health Surveillance (CIGASS).

The aim of the event was first and foremost to launch the activities of the ASC and to enable young Senegalese researchers, teacher–researchers and engineers working in the fields of crystallography, material sciences, chemistry and biology to get to know each other through the presentation of the different activities of their home laboratories, and to encourage interactive exchanges between specialists and novices in crystallography. Particular attention was paid to the new CNRS/CRM² AFRAMED project (Doctoral Training and Research in Africa through remote X-ray diffraction measurements), a remote laboratory led by Professor Claude Lecomte. Launched on 31 August 2022, this project enables scientists from African laboratories to remotely control the CRM² single-crystal X-ray diffractometer located at CRM², Université de Lorraine, Nancy, France. This conference day was attended by 81 participants from five Senegalese public universities: Assane Seck University of Ziguinchor (UASZ), Alioune DIOP University of Bambey (UADB), Gaston Berger University of Saint-Louis (UGB), Amadou Mahtar Mbow University of Diamniadio (UAM), Iba Der THIAM University of Thies (UIT) and, of course, Cheikh Anta DIOP University of Dakar (UCAD).

3. The 2024 edition

Course of activities

The scientific day began under the auspices of the university authorities. The opening ceremony was presided over by Professor Bassirou Lô, Dean of the Faculty of Science and Technology at UCAD, representing the Rector, in the presence of the Head of the Chemistry Department, Professor Momar Ndiaye, the Director of Pedagogical Affairs (DAP) and many other leading figures from the Senegalese scientific world.

The event began with an official welcome address by Professor Ibrahima Elhadji Thiam, Chair of the day's organizing committee (UCAD), followed by words from Professor Magatte Camara, ASC President (UASZ); Professor Emeritus Claude Lecomte; Professor Momar Ndiaye; and Professor Bassirou Lô.

Immediately after the opening ceremony, we moved onto the inaugural lecture by Professor Lecomte entitled "Crystallography in Sub-Saharan Africa: Contribution of AFRAMED to the CNRS-IUCr-UNESCO Africa Initiative”.

Why this conference? To understand the importance of developing crystallography and structural sciences in Sub-Saharan Africa. By answering the question: What is crystallography? Prof Lecomte showed that it is an essential science at the crossroads of disciplines such as mineralogy, geology, physics, chemistry, materials and life sciences.

The AFRAMED project was prompted by the emergence of COVID-19, with its widespread travel constraints. In 2022, the CNRS decided to give priority to collaborations with Africa and created the AFRAMED IRN (International Research Network) proposed by Professor Lecomte. AFRAMED is a five-year CNRS project: during one month, three or four young African colleagues are trained intensively to 'drive' single-crystal diffractometers by CRM² researchers (Dr Emmanuel Wenger, Dr El-Eulmi Bendeif and Professor Lecomte). Then, back in their home country, these colleagues can collect diffraction data on the CRM² diffractometers in remote mode for teaching and research. Since September 2022, Egypt, Togo, Cameroon and Gabon, Senegal, Congo Brazzaville, Ivory Coast and Algeria have been involved; in 2024, Madagascar, Burkina Faso and Mauritania will be the hosts of CRM². The trainees are fully funded by the CNRS IRN and the IUCr within its Crystallography in Africa initiative. UNESCO will join in 2024.

During the conference day, a remote session on single-crystal X-ray diffraction was led by Dr Wenger. Emmanuel centered a paracetamol single crystal on the diffractometer and taught all steps of XRD data collection. We noted great enthusiasm from the participants.

Researchers from eight research teams and laboratories in Senegal reviewed their research work in oral presentations, giving a brief overview of the research team, highlighting the use of the diffractometer – an iconic instrument in crystallography –, the contribution of crystallography to their field of research and their prospects.

Laboratory of Chemistry and Physics of Materials, LCPM (UASZ)

The Materials Chemistry and Physics Laboratory (LCPM) was established in 2010 and recognized by a Rector's decree in 2017. It is attached to the Sciences and Technologies UFR and Science, Technology and Engineering (STI) Doctoral School. Its current Director is Professor Magatte Camara, assisted by Professor Lat Grand Ndiaye. The LCPM has published over 300 publications and patents, and collaborates with 22 partner laboratories worldwide. Its research themes involve rare-earth-based inorganic materials, microporous and nanoporous materials, switchable materials, crystallography, materials engineering (ceramics, single crystals, thin films, nanostructures, waste recovery, biomass, biogas etc.), the chemistry of natural substances (extraction, isolation, characterization, fine chemical recovery) and synthesis methods for innovative molecules and molecular materials.

Organic Coordination Chemistry Laboratory, LCCOB (UCAD)

The Laboratoire de Chimie de Coordination Organique et des Biomolécules (LCCOB) was set up in 1998 by Professor Abdou Salam Sall and Professor Mohamed Lamine Gaye. It belongs to the Faculty of Science and Technology and the PCSTUI (Physics, Chemistry, Earth, Universe and Engineering Sciences) Doctoral School. Its current Director is Professor Ousmane Diouf, and it collaborates with several national faculties and institutes and with various public universities in Senegal. Collaborations with international laboratories include the universities of Marseille, Toulouse, Nancy, Grenoble, Paris, Tunis, Nouakchott, Conakry, Algiers, Lyon, San Carlos (Brazil) and Southampton (UK). Over 200 articles have been published in international journals. Its field of research is the synthesis of homonuclear and heteronuclear coordination complexes, and transition metal and lanthanide co-crystals from Schiff bases. The physico-chemical and biological properties of the molecules are studied.

Physical, Mineral, Organic and Therapeutic Chemistry Laboratory, LCPMOT (UCAD)

The Organic and Therapeutic Chemistry Laboratory, more than 50 years old, recently renamed the Physical, Mineral, Organic and Therapeutic Chemistry Laboratory (LCPMOT) according to the subjects taught, is housed within the Department of Pharmaceutical, Physical and Chemical Sciences of the Faculty of Medicine, Pharmacy and Odontology (FMPO) of UCAD. The main line of research focuses on the synthesis of ligands and transition metal coordination complexes with biological activity. Most complexes have antioxidant activities (evaluated with the DPPH radical) greater than those of the ligands, and the diazenes obtained present antimicrobial and anticancer activities on several tumor lines.

Inorganic and Analytical Chemistry Laboratory, LACHIMIA (UCAD)

Founded in 1978 by Professor Libasse Diop and currently headed by Professor Mamadou Sidibé, the Inorganic and Analytical Chemistry Laboratory (LACHIMIA) uses crystallography as one of its main methods for characterizing molecular structure and materials in general. LACHIMIA is involved in three major areas of research, namely coordination chemistry, mining environment and water chemistry. In the field of coordination chemistry, LACHIMIA favors single-crystal X-ray diffraction analysis to elucidate the structure of their materials. For the study of mining environments, particularly mine tailings and clay materials, X-ray powder diffraction is used to characterize their mineralogy and analyse their crystalline phases. LACHIMIA has characterized over 200 crystal structures of coordination compounds, resulting in more than 100 publications in international journals. Recently, the laboratory has also undertaken X-ray diffraction characterization of mine tailings from SABODALA and clays from various regions of Senegal, in collaboration with the SANTARGILE Company.

Quantum Energy Photonics and Nanofabrication Laboratory, LPQEN (UCAD)

The Quantum Energy Photonics and Nanofabrication Laboratory (LPQEN) is headed by Professor Balla Diop Ngom. LPQEN is a laboratory working on the synthesis and characterization of nanomaterials such as activated carbon, two-dimensional materials (graphene, MXene), metal oxides, metal oxi-nitrides, composites and nanocelluloses. The materials are characterized using various techniques to study their physico-chemical properties. These nanomaterials are used in supercapacitor electrodes. The experimental facilities of the laboratory are electric and chemical vapor deposition (CVD) furnaces, a 16-channel VMP300 Static Potentiometer, an 8-channel battery analyzer, an autoclave with a heating jacket and a pressure-controlled button cell crimping machine.

Chemistry of Inorganic and Organic Materials team, ECMIO (UADB)

The ECMIO research team, headed by Professor Farba Bouyagui Tamboura, is attached to the Physics-Chemistry doctoral program of Applied Sciences and Computer and Communication Technology UFR, Department of Chemistry of UADB. It has to its credit 57 publications in indexed and abstracted journals, and 17 oral presentations and 11 poster presentations at various conferences and seminars. Partner universities and institutes are UCAD; UASZ; the universities of Nouakchott (Mauritania), Strasbourg (France) and El Manar Tunis (Tunisia); and the Jean Rouxel Materials Institute (Nantes, France). Work focuses on organic and inorganic synthesis; complexation, magnetic, conductimetric, antifungal and antibacterial studies; and X-ray diffraction.

Environment - Engineering - Telecommunications and Renewable Energies Laboratory, LEITER (UGB)

LEITER is a laboratory that tackles issues linked to the production of scientific knowledge on renewable energies, energy efficiency and water and environmental engineering, from materials and their transformation to technological and engineering innovations to achieve greater energy efficiency in their use. The Laboratory promotes multidisciplinary research activities with a potential impact on the sustainable development of Senegal and Africa. LEITER comprises three multidisciplinary teams: Electronics-Electrotechnics-Automatics and Computing; Renewable Energies and Materials; and Water, Environment and Climate. Professor Amadou Seidou H. Maiga is the Director and he is assisted by Professor Elhadji Babacar Ly, who is a lecturer and researcher in materials chemistry at UGB. He conducts research into materials and their transformation for various applications such as construction materials, biocomposites, conductive polymers, paper and plastic packaging, membranes for water treatment, biogas and biofuel. He uses crystallography and diffractometers to identify chemical species and phases in materials, to design the best combinations of materials for a given application, and to interpret the results of his research.

X-ray Utilization Laboratory, LUX (FST-UCAD)

The LUX laboratory research team is currently headed by Dr Abdou Ciss Wade. LUX was set up in the Physics Department in 2000 by Professor Djibril Diop, with the help of the X-ray physics group at the University of Trento in Italy. In 2005, the lab was equipped with a Philips PW 1840 diffractometer, with Bragg–Brentano geometry θ–2θ, and in recent years has turned its attention to the study of local materials such as binders made from sewage sludge ash and lime, clays, eggshell powder etc. The objectives revolve around the design of materials by promoting interactions between technologies on the one hand, and physics and chemistry on the other; the development of composite materials with specific properties; understanding the electronic, structural and thermal behavior of fullerenes and fullerites; and determining the mechanical, physical, thermal and chemical properties of local materials (soils, ashes, clays, eggshells etc.). The laboratory collaborates with the Ecole Supérieure, UIT, University of Trento and Synchrotron Elettra (Trieste, Italy) and Université Gustave Eiffel (Paris, France). The laboratory has organized three international X-ray workshops, which took place in December 2005, January 2009 and January 2012.

The following article appears as the Foreword to Volume I of International Tables for Crystallography, X-ray Absorption Spectroscopy and Related Techniques.

Volume I of International Tables for Crystallography, X-ray Absorption Spectroscopy and Related Techniques, is a welcome and very timely addition to this encyclopaedic series of volumes, fitting well with the statement of purpose of the International Union of Crystallography (IUCr), ‘Advancing structural science globally’, that was revisited as part of the 75th anniversary of the organization in 2023. X-ray absorption spectroscopy (XAS) and related techniques such as X-ray emission spectroscopy (XES) complement other structural techniques that are the subject of previous volumes well, expanding the reach and coverage of International Tables.

Although there are many excellent books and manuals describing XAS and related techniques, including both practice and theory, there are none as complete or comprehensive as Volume I. The range of topics covered by the present volume is extremely extensive, from the instrumentation needed to perform the experiments, describing the data reduction and analysis, discussing important considerations when preparing samples, presenting theoretical approaches and the statistical significance of the results, and highlighting applications. Each of the nine parts in the volume addresses a specific aspect that is relevant to those who regularly use XAS and related techniques, but also to those who are novices and who would like to understand the potential of using spectroscopy for detailed structure determination. The three Editors have done an exceptional job in attracting many contributions from world experts on the topics covered by the volume, and this is shown in the quality of the final product. The overall result is a very coherent and self-contained volume.

I believe the contents of Volume I will attract interest from a wide variety of researchers. Scientists working on synchrotron beamlines will find that the Experimental methods part (Part 3) is an excellent manual describing the instrumentation needed to perform X-ray spectroscopy measurements, and the detectors needed for optimal experiments. It will also serve as a guide for experimentalists interested in improving data quality by optimizing sample preparation and data-collection methods. For those more interested in the fundamentals of the technique, I would recommend Part 2, Theory, which includes the theoretical approaches and approximations most often used for the interpretation of XAS and other techniques such as diffraction anomalous fine structure and X-ray magnetic circular/linear dichroism. In my opinion, researchers interested in using XAS for the first time will enjoy Part 5 (Analysis of experimental data), which is an excellent compendium of the many steps required for XAS data reduction and analysis. Personally, as a spectroscopist and expert XAS and XES user, I have found Part 6, Packages and approaches for data collection and data reduction, very useful. Descriptions of many of the most frequently used software packages for XAS and XES data analysis and simulations are included, with most of the chapters written by the developers of the codes, and openly discussing their strengths and their limitations. This is a unique feature of the volume, and no other publication exists where all this information can be found in one place. The Applications part (Part 8), which focuses on examples showing the applicability of the techniques, will attract the interest of scientists working in many different scientific areas, from catalysis to battery materials, environmental science, bioscience, cultural heritage and many more.

Volume I is consequently a very comprehensive compilation of the fundamentals, state of the art and future directions of XAS and related techniques. I have every expectation that it will become a classic reference text for any expert in the field, but also as a starting manual for those who would like to learn more about the techniques and use them in their research.

It has been a year since the successful IUCr Congress and General Assembly in Melbourne and we are looking forward to the 2026 event in Calgary. This past year has been one of contemplation of our future as an association, a year of change and renewal.

Our Union is based on the significant personal contributions that have graciously built our organization since 1948. Our Chester office is a key part of our functioning, maintaining our activity and planning our future, our resources and optimizing our funding sources to carry out the good works aimed at promoting and defending structural science globally. At the end of May, our Outreach Officer since 2014, Michele Zema, concluded his contract after 10 years of excellent contributions to the IUCr. These contributions have marked a new era in the collaboration and promotion of structural science mainly in Africa, Latin America and Asia, bringing in a substantial amount of funding and creating successful initiatives such as the 'OpenLabs', new labs with modern equipment for structural science in less-developed countries and the light sources within the LAAAMP project.

The impending retirements of Peter Strickland and Andrea Sharpe will have a great impact on our activity in Chester and bring an extraordinary emotional burden. Peter will retire from his post as Executive Managing Editor in September after 38 years of the highest responsibilities, not only in our editorial team but also in a position of leadership at Chester and at the IUCr. Peter will be impossible to replace and his generosity will surely allow us to continue to count on his advice and help in the time that his new occupations allow him, especially when the tasks in his garden become less intense.

It will be difficult to imagine the IUCr booth at the different congresses without Andrea or without her contribution to the publication of the four issues of the Newsletter that we publish every year. Andrea joined the IUCr in 1980 as an Editorial Assistant, left in 1990 and returned in 1998 as the Promotions Officer; her retirement completes a career of nearly 36 years of service.

We will always be indebted to Peter and Andrea (seen below with Michele during preparations for the 2017 Hyderabad Congress), who are part of our brilliant history, and to whom we are deeply grateful for having dedicated such an important part of their lives to the service of the community of structural scientists.

In this first year between Congresses the scientific protagonism lies with our Regional Associates (RAs). The American Crystallographic Association gathered in Denver, CO, USA, in July; the European Crystallographic Association will meet in Padova, Italy, in August; the Latin American Crystallographic Association will meet in Montevideo, Uruguay, in September; and the Asian Crystallographic Association will meet at the beginning of December in Kuala Lumpur, Malaysia. The African Crystallographic Association will meet in Algeria in April 2025.

It is pleasing to note that the 18th European Powder Diffraction Conference (EPDIC18) is being organized jointly with ECM34 in Padova. This arrangement is very satisfying for both organizations as they have common interests, and worked well when EPDIC12 overlapped with ECM26 in Darmstadt in 2010. The attendance will benefit from the joint organization.

Although the Executive Committee (EC) will be represented at all regional meetings at the highest level, this year the EC and the Finance Committee (FC) met in Denver at the 74th ACA Annual Meeting. Given the importance of the upcoming IUCr Congress and General Assembly to be held in Calgary, Canada, in August 2026, this visit and the meetings with the ACA Council and the IUCr2026 Organizing Committees were essential. In particular, it was important to discuss the plans for the formation and the work plan of the International Program Committee and other organizational and financial issues.

All the discussions took place in a splendid atmosphere and at a high scientific level, and the participation of the young generation of structural scientists was excellent. Learning about the many initiatives that the ACA is putting in place was also extremely satisfying for the IUCr EC. A closer collaboration between the RAs and the transfer of good practices between the different regional and national associations was found to be desirable.

In parallel, the FC analysed the Union's financial situation and adopted cost containment measures for 2024 and 2025, pending growth of our publishing revenues. Decisions were also taken on the investment of our funds and the desirability of augmenting the FC with new advisors to complement the current profiles and contribute to the diversity and rejuvenation of the committee.

At the moment, 55 National Committees make up the IUCr General Assembly. Until the goal of incorporating all countries where there are structural scientists is achieved, the Associates Programme is an excellent way to become an individual member of the IUCr and enjoy the benefits associated with publishing in the 10 IUCr journals and other advantages that will be progressively increased, especially for younger Associates.

Now that the statutes of the International Science Council (ISC) have been approved and the election of the Elections Committee has taken place, the election process for the renewal of the ISC Governing Board has started. The IUCr, together with the other ISC member unions, is promoting a candidacy that defends the philosophy of rigorous and global science that the scientific unions promote.

Once again, many thanks to all those who form and make our organization work: the RAs, the IUCr Commissions and Committees, Editors, Co-editors, referees and authors of our journals, our Chester staff and all individual crystallographers, women and men.

Thanks to IUCr Newsletter Editor Mike Glazer, his team, with one special mention to Andrea, and all contributors for making possible, as every quarter, a new quarterly issue and for continuing to be the communication reference for our community.

Many thanks to all for helping to sustain and reinvent the IUCr from wherever you are in the world.

Enjoy your summer holidays!

It is with heavy hearts that we write this memorial for Dr Richard Alexander Pauptit, who died on 30 June 2024. Richard was well known and highly respected in protein crystallography circles and contributed hugely to the field. His enthusiasm, passion, and creativity for this area of structural biology was infectious, and those who were fortunate to work, study and collaborate with him will feel a profound loss on his passing.

Richard was born in Amstelveen, in the province of North Holland, Netherlands in 1954. Due to his father’s work, he spent his formative years travelling the globe including time in the Middle East, Europe, Australia and Africa, and the love of travel continued throughout Richard’s adult life.

Richard completed his schooling at the American Community School in Beirut, Lebanon, before enrolling at the University of Cape Town, South Africa (1973–75) where he received a BSc and excelled in Chemistry and Computing. It was during his time as an undergraduate that Richard’s interest in X-ray crystallography was sparked. Richard began working in the field of small molecule crystallography in the laboratory of Professor Luigi Nassimbeni at the University of Cape Town, helping to solve four small molecule structures.

Richard’s academic journey continued at the University of British Columbia, Vancouver, Canada, where he undertook an MSc (1976–78) and PhD (1978–1982) in the laboratory of Professor James Trotter. Here, he honed his understanding of crystallography in the field of chemical crystallography, working on organic compounds.

Richard continued to build on his knowledge during a postdoctoral and lectureship position (1982–83) at the University of Auckland, New Zealand, which resulted in the publication of several small molecule structures.

In 1983, moving across the globe again, Richard took up a research position in the Biocenter at the University of Basel, Switzerland with Professor Johan Jansonius. At this stage Richard extended his research activities to the study of macromolecules. Using his broad crystallography background and programming skills, Richard wrote and improved a wide range of computational programs in the area of molecular replacement and protein structure refinement. At the Biocenter, he led and collaborated on many challenging projects including proteases, transaminases and other enzymes as well as the nascent field of membrane protein crystallography on a number of different porins.

In 1991, Richard moved to Heidelberg, Germany, to become a Fellow with the European Molecular Biology Laboratory (EMBL), working with many current leaders in structural biology. At EMBL his scientific collaborations focused on Src homology 3 domains and other related proteins.

Following this research position, in 1992, Richard took up a Team Leader position with AstraZeneca pharmaceuticals (formerly known as ICI Pharmaceuticals), in Macclesfield, United Kingdom. He established protein crystallography facilities and integrated this technique into an ongoing programme of drug design. Together with other scientists, under Richard’s leadership, target-compound complex structures were determined which led to development of many drug therapies for disease.

As a Senior Principal Scientist and Associate Director in Discovery Sciences, Richard continued to inspire and innovate, ensuring that scientists could collaborate, within and outside of the company, encouraging rich partnerships with universities and research institutes. He played an important role in various outreach initiatives, including a postdoctoral programme whose aim is to promote a supportive and collaborative research culture for scientists to thrive. Richard brought the crystallography group in AstraZeneca to both national and international arenas. He participated in and led many collaborative and strategic activities including: leadership of the Biological Structures Group of the British Crystallographic Association; he was an active member of the CCP4 committee; a member of Scientific Advisory Board for BIOXHIT (an EU Framework 6 high-throughput crystallography project); was a Member of the Scientific Advisory Committee for the Membrane Protein Structure Initiative (MPSi), a BBSRC SPoRT initiative; and was a peer reviewer for JMB, Structure and many other journals, including IUCr Journals where he also acted as a Co-editor on Acta Crystallographica F.

Richard instigated communities of practice and founded opportunities to share expertise and research news, including the international Protein Structure Determination in Industry (PSDI) meetings and the CCP4 Glasgow Protein Structure Workshop, a Northern UK regional protein crystallography event involving around 10 academic laboratories and AstraZeneca.

Richard was a leading voice in the world of protein crystallography with a long list of invited lectures at meetings and conferences. With his expertise in drug discovery, he held honorary positions in academia in addition to supervising researchers and being a PhD external examiner. He had an amazing portfolio of collaborations and authored many publications, but the wealth of influence he had on so many projects is priceless.

To have encountered Richard, to have worked with him and interacted in some way along his globe-trotting scientific journey is an unforgettable experience. Many people will have listened to, and have been inspired by, his talks at various conferences and lectures at universities. Colleagues will have sat with him on various committees and organized meetings and conferences with him, and will be marked by these encounters. As his former students, we were fortunate to benefit from his unorthodox yet effective teaching methods. His approach was always centered around the individual, offering a unique perspective on research and teaching: the strong, black coffee he served kept us going through the long periods of data collection; the crystallography tutorials delivered in the safe learning environment of the local pub will be forever etched in our memories; and the nail-biting journeys of course, in a battered, left-hand drive Volvo were character building.

Richard may have introduced us to crystallography, but his influence remains with us over the course of our varied careers. He taught us with humility, he was the most supportive, warm, funny and unusual mentor. He formed a community who were bonded by a scientific goal but also united a team through kindness, generosity and karaoke.

Richard retired from AstraZeneca in 2014 and spent time developing many of his other skills and talents. A big fan of motorbikes and skiing, he once stated that he enjoyed the feeling of the wind fast flowing through his long hair. He had a passion for music, played the guitar and was always keen on introducing people to lesser-known Canadian guitar bands. In latter years, Richard explored his creative side, demonstrating a talent in painting and exhibiting his art several times. He was an active member of a crossword setting community, sharing his method of setting, and solving puzzles on a regular basis. Many readers of The Independent will have in fact struggled with cryptic crosswords set by ‘Dutch’, Richard’s alias as a puzzle setter.

Richard is survived by a loving family who have been a constant source of strength and inspiration for him. His children made him proud and will carry his generosity of spirit with them. Richard will be remembered not only for his scientific achievements and creative endeavors but also for his kindness, generosity, and the indelible mark he left on the lives of those who had the privilege to know him. A unique man, who will be sorely missed.

This article was previously published in Acta Cryst. (2024). F80, 191–192.

The IUCrJ theme of Chemistry and crystal engineering covers a broad range of topics and this is reflected in the articles published in IUCrJ. In 2022, Desiraju suggested that 'the Holy Grail of crystal engineering is to answer the question: Given the molecular structure of a compound what are all the possible crystal structures?' (Desiraju, 2022). It is interesting and instructive therefore to reflect on advances made towards this goal in recent years. While there is still a focus in crystal engineering to deepen our understanding of the influence of intermolecular interactions on crystal packing, increasingly the focus has moved to practical applications such as devices and materials with useful physical and chemical properties (Braga, 2023; Xiong et al., 2024; Kasuya et al., 2024; Xu et al., 2024). Recent articles in the journal highlight developments both in methodology and techniques as well as a diverse range of classes of compounds being studied and of problems being tackled.

Studies on the nature of non-covalent interactions are highly topical (Biot & Bonifazi, 2020; Rajapaksha et al., 2023) and are well represented in recent publications in the journal. These include the nature of π-hole interactions between iodide anions and quinoid rings which have been shown to be predominantly electrostatic (Milašinović et al., 2023) while Carroll and co-workers used a crystalline sponge to isolate and characterize a family of biaryl alcohol guest molecules, showing that the orientation and molecular conformation adopted by the guest molecules is controlled by the intermolecular interactions (hydrogen-bonding, halogen-bonding and/or aromatic interactions) available at the guest exchange site (Carroll et al., 2023).

Interesting questions remain, such as how far can a packing motif change while still being considered the same? This is the subject of a re-evaluation of the definition of isostructurality (Bombicz, 2024) which argues that consideration of symmetry and supramolecular interactions and their influence on the resulting crystal structure is required. The concept of similarity and isostructurality is key to the study of polymorphism (Subanbekova et al., 2024; Jeziorna et al., 2023) and even of the disappearance and reappearance of polymorphs (Sacchi et al., 2024). A recent example of the value of such considerations is the study of the mechanism and kinetics of transforming polymorph C of the pharmaceutical ingredient ibrutinib to its halogen benzene solvates using a flow-through capillary mounted directly on a powder X-ray diffractometer (Jirát et al., 2023). Four different transformation mechanisms were determined despite the isostructurality of three of the four solvated crystal structures. The influence of environmental factors on molecular packing is another area of ongoing interest. The increasing availability of diamond-anvil cells has promoted an interest in the effect of pressure on molecular packing. High pressure promotes some interactions over others and can force the molecules to adopt a particular conformation (Sacharczuk et al., 2024) while pressure changes can induce migration of a proton to allow interconversion between a cocrystal form to an ionic salt (Patyk-Kaźmierczak et al., 2024).

Crystallography may be said to have reached a mature phase as a science but new techniques and computational approaches are essential to allow researchers to tackle ever more complex problems. Recent developments in quantum crystallography hold great promise for improving the accuracy of key structural parameters. For example, Hirshfeld atom refinement (HAR) uses aspherical structure factors obtained from calculation to produce more accurate structural information such as more accurate hydrogen atom positions even in cases where the hydrogens are close to heavy elements (Capelli et al., 2014; Woińska et al., 2023). Zwolenik et al. (2024) applied HAR to a molecular structure at high pressure and compared the result with an analysis of the same structure measured over a temperature range of 90 to 390 K.

Developments in machine learning and artificial intelligence will have an increasing impact on the nature of the questions that can be addressed using crystallography (Ekeberg, 2024; Billinge & Proffen, 2024; Zhu et al., 2024). An intriguing example is recent work by Takiguchi et al. who devised a deep learning model to determine which of 20000 metal complexes extracted from the Cambridge Structural Database (CSD) are single-molecule magnets (SMM) with 70% accuracy (Takiguchi et al., 2024). The latter article highlights the enormous value the CSD (Ferrence et al., 2023) and other databases offer so it is encouraging to see the work being done by CODATA to ensure the interoperability of crystallographic data within the FAIR principles (findable, accessible, interoperable and reusable) (Brink et al., 2024).

In conclusion, recent articles in the journal are evidence that crystal engineering concepts are well embedded in many aspects of chemical crystallography. Further advances in these themes are to be expected and will be welcomed in IUCrJ.

References

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Biot, N. & Bonifazi, D. (2020). Chem. Eur. J. 26, 2904–2913.

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This article was originally published in IUCrJ (2024). 11, 434–435.  

The article by Olech et al. (2024) in this issue of IUCrJ marks an important step forwards in accessing some of the wealth of information that can be obtained from materials using electron diffraction (ED). It brings together an accurate description of electron scattering and quantum crystallography models of bonding between atoms in a crystalline solid. The field of ED is developing rapidly at the moment, as quantitative measurements and computer control of electron microscopes [and indeed dedicated electron diffractometers (White et al., 2021; Merkelbach et al., 2022)] are beginning to give routine access to high-quality data that has for so long been the norm in X-ray diffraction (XRD) and neutron diffraction (ND). Approaches that have been developed over decades in the latter two fields are now being applied to ED, opening up whole new fields of investigation, particularly for nanoscale crystals that can be easily studied by electrons due to their much stronger interaction with matter.

This strong interaction, inherent in electron diffraction – and resultant multiple scattering – brings many benefits that are beyond the reach of measurements where single scattering dominates. Friedel’s law, mandating equivalence of the intensity of reflections related by inverting the scattering geometry, does not apply, allowing absolute structure to be determined (Buxton et al., 1976; Brázda et al., 2019). Additionally, low-order structure factors may be measured much more accurately using ED in comparison with XRD or ND, giving the chemical (bonding) information that is the focus of this article. However, access to the rich and deep information available in ED comes with the cost of increased complexity in the models required to give a good description of the data and the desired measurements.

The benefits, and limitations, of ED have been apparent for some time (Spence, 1993) and bonding effects were determined using dynamical scattering theory in combination with convergent beam electron diffraction (CBED) patterns over thirty years ago (Zuo & Spence, 1991). Nevertheless, the measurement was not straightforward, requiring manual control of both the transmission electron microscope (TEM) and the crystal goniometer to select and orient a suitably defect-free region of a thin crystal for the diffracted beam(s) of interest; recording the pattern on film; digitizing the negative; and refining to a solution using the limited computing resources of the time. The result was a handful of low-order electron structure factors that, in combination with higher-order structure factors determined by XRD, could be used to measure deviations from the neutral, spherical atoms of an independent atom model (IAM) (Zuo et al., 1999).

Olech et al.’s article clearly shows that the success of CBED can be replicated by the various techniques that fall under the acronym 3DED (Gemmi et al., 2019). Importantly, computer control of both the electron optics and the noise-free detectors of current methods makes them relatively straightforward experimentally. Furthermore, the use of a parallel beam removes the restriction on lattice parameters imposed by CBED, in which the convergence angle must be smaller than the smallest Bragg angle in the diffraction pattern. These advantages mean that 3DED techniques are relevant to materials that are of interest to a wide range of scientists and crystallographers. Here, the material chosen to demonstrate the approach is an organic, beam-sensitive molecular crystal, which yielded only a few reliable measurements even with specimen cooling. That a refinement performed on this less-than-ideal data using an aspherical multipolar atom model not only gave a significantly better match between model and experiment, but yielded chemically sensible results, demonstrates the strong influence of bonding effects in ED and is very encouraging for future studies. Furthermore, the ability to qualify different versions of transferable aspherical atom model (TAAM) against experimental data as demonstrated in this article will undoubtedly drive improvements in quantum crystallography.

This article is yet another demonstration that improvements in technology, technique and modelling in ED are opening avenues of research that previously have been only partially visible. There is yet some distance to travel.

References

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Gemmi, M., Mugnaioli, E., Gorelik, T. E., Kolb, U., Palatinus, L., Boullay, P., Hovmöller, S. & Abrahams, J. P. (2019). ACS Central Science, 5(8), 1315–1329.

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This article was originally published in IUCrJ (2024). 11, 277–278.