The IUCr Newsletter is the web magazine of the International Union of Crystallography. Since 1993, the IUCr Newsletter has been published quarterly and distributed to over 13,000 crystallographers worldwide. In January 2025, it transitioned to a bi-monthly publication. Its aim remains to bring together the crystallographic community.
At last, summer is upon us. Over here in Europe, we were recently “treated” to an incredible heat wave (canicule in French), breaking all records for the month of May. But now we return to the usual UK weather: cold, windy, and drizzly. So far, June is not looking much better, but there are ominous warnings for a very hot July. Ho, hum!
As some of you may be aware, I am always interested in the history of our subject. Recently, a colleague found in a second-hand bookshop in Oxford the book entitled The Universe of Light (1933) by Sir William Henry Bragg (WHB). WHB evidently gave this book to C.H. Jenkinson, who was WHB’s personal workshop technician, responsible for building the first ionisation spectrometer circa 1912, the forerunner of the modern X-ray diffractometer. The book was originally priced at four shillings and sixpence (about 23 UK new pence at the time).
One of my sad duties for the Newsletter is to report obituaries. In this issue, three colleagues of mine, Wolfram Saenger, Sax Mason and Svend Erik Rasmussen. I recall first meeting Wolfram many years ago at a summer school in Poland. He was an engaging (then young) man, very interesting to talk to. He had a fascinating party trick in which he demonstrated that he could write simultaneously with both hands, each the mirror image of the other. I think this is called Bimanual mirror writing, and is relatively rare and sometimes researched by neurologists.
Sax Mason was a scientist whom those of us who have ever carried out research at the Institut Laue-Langevin (ILL) came across. I recall meeting him the first time I measured powder patterns at the ILL, as Sax was always there to guide us. I am sorry to hear of his loss.
I recall that at IUCr Congresses I always met with Svend Rasmussen, who was then General Secretary of the IUCr (the General Secretary of the International Union of Crystallography (IUCr) was the Union’s chief administrative and operational officer, responsible for keeping the organisation running smoothly between General Assemblies). He was always a delight to talk to: friendly, quiet, and we shared many similar views. His passing is one of personal deep sadness as I came to know him as a personal friend. One thing I learnt from the obituary is that in the 1950s, he spent time in the Chemistry Department at Queens College, Dundee, Scotland. I too was there, but much later (1962-1965) to study for my undergraduate degree in Chemistry. At that time, Queens College was one of the Colleges of the University of St Andrews, but later it became independent as the University of Dundee.
Turning to more pleasant matters, since the beginning of the 20th century, crystallographers have always been pioneers in the collection and publishing of data. For a long time, crystallography was just about the only discipline that produced large datasets, especially diffraction intensity data. When computers became available, many of the algorithms we use today as routine were developed with crystallographic data in mind. For instance, the earliest systematic use of computer based least squares refinement occurred in X ray crystallography, starting around the 1940s, when researchers began using electronic computers to refine atomic positions and thermal parameters from diffraction data. This predates its widespread use in physics, geodesy, astronomy, and statistics by several years. It may be said that the crystallographer’s love affair with data began as far back as 1913, when W.H. and W.L. Bragg published their measurements and interpretations as a matter of routine. So, in this issue you can read an article discussing the importance of data.
One of the most important things that any crystallographer needs to learn about is the mathematics of symmetry. Yes, I know that these days you can solve structures with an automatic diffractometer without the need to know much about symmetry, but to me, that is not real science. I guess, at my age, I am old-fashioned (grumpy old man syndrome?). Anyway, one of the mainstays of our use of crystallographic symmetry is found in the series of books known as the International Tables of Crystallography. In particular, any crystallographer worth his/her salt should know about the so-called 230 space group types, and this is what the Tables give us. The first full published compilation was in 1935 and was written in German. Since then, the Tables have undergone some evolution, first in 1952, when they were recompiled by Norman Henry and Kathleen Lonsdale. Then later on, the Tables were revisited by members of the International Commission on Tables, and much new material was added, especially with tighter definitions of terms used in our subject. The result has been an amazing compilation of definitions and explanations of crystallographic terminology, though sometimes hard to read, it is nonetheless thorough. Oh, I remember many times attending meetings and sometimes seeing heated discussions among colleagues voicing their own ideas, often at odds with the majority opinion. One of the contentious matters then was the vexed question of whether there were 6 or 7 crystal systems, a problem arising from the presence of 3- and 6-fold symmetries (6-fold symmetry also contains 3-fold symmetry). In the end, the Commission settled on 7 in order to be consistent with most earlier usage. Anyway, what has resulted is what I sometimes say is the greatest book ever written! But then I am prejudiced, of course. Now, one of the odd leftovers is the question of the order in which the space group types are listed and numbered. This has been revisited in a recent publication written by Mois Aroyo and Carol Brock, which you can read about here.
We also have the second article by Zbigniew Dauter and Mariusz Jaskólski, dealing with the packing of spheres in cubic space groups. Packing of spheres is one of those subjects that we crystallographers are familiar with, since, to a reasonable approximation, we can usually treat atoms in a crystal structure as akin to spheres.
Another article that you may find interesting is on the development of Cryo-EM in Portugal by Célia V. Romão and Pedro M. Matias. Cryo EM is electron microscopy performed on flash frozen samples, allowing researchers to see proteins, viruses, and other macromolecules in a state very close to their natural environment, and was the subject of the Nobel Prize in Chemistry in 2017, awarded to Jacques Dubochet, Joachim Frank and Richard Henderson. The equipment for this is expensive, and it is a great achievement of the Portuguese researchers to be able to obtain the funding for such an important research tool. Strictly, this is not crystallography.
Finally, let me add that in August of this year, crystallographers will be gathering together to attend the IUCr Congress of Crystallography, to be held in Calgary, Canada. So if you have not yet signed up for this, do not lose the opportunity to be able to meet with fellow crystallographers and learn about the latest in our amazing science!
Professor, Dr Phil. Svend Erik Rasmussen passed away on the 3rd of April 2026 at the age of 100. He was one of the founding professors of the Department of Chemistry at Aarhus University when it was established in 1960, and he left a profound mark on both Aarhus University and Danish chemistry.
Svend Erik was born on the 19th of November 1925 in Esbjerg and obtained his Mag.Scient. degree in chemistry from the University of Copenhagen in 1950. After short appointments at the Royal Veterinary and Agricultural University and the University of Copenhagen, he spent a year at Queen’s College in Dundee before being appointed at the Technical University of Denmark in 1952. He became Professor of Inorganic Chemistry at Aarhus University in 1959, where he established numerous research areas until his retirement in 1995. After his formal retirement, he continued his academic work as Professor Emeritus at the Department of Geoscience until 2017. He was elected to the Royal Danish Academy of Sciences and Letters in 1981.
Svend Erik obtained his Doctor of Science degree in 1960, and his research focused particularly on crystallographic studies of inorganic compounds. He was an early adopter of computer-based calculations in chemical research, and under his leadership, Danish crystallography flourished in the 1960s and 1970s, gaining significant international recognition.
By recruiting excellent scientific and technical staff, Svend Erik’s inorganic division built an extensive instrumentation infrastructure with emphasis on diffraction equipment, and the division had high research activity, particularly within solid-state chemistry. He established the department’s strong tradition of exceptional mechanical and electronics workshops for developing unique scientific equipment. With remarkable foresight, he also involved Aarhus University in the utilisation of the DR3 nuclear reactor at the Risø National Laboratory by securing funding and personnel to build and operate a neutron diffractometer for advanced crystallographic research.
Svend Erik consistently pursued new avenues and established close ties with Danish industrial companies, for whom he conducted advanced scientific measurements as part of revenue-generating activities. He had strong international connections, particularly with French research environments, and in 1980, he was appointed Officier dans l’Ordre des Palmes Académiques. For many years, he contributed to public science communication as the author of numerous articles for the Danish National Encyclopedia. He maintained an extensive international scientific network and held a number of positions of trust, including serving as General Secretary and Treasurer of the International Union of Crystallography from 1972 to 1981, where he bore a strong responsibility for administering the Union's finances and developing the organisation. Svend Erik also arranged successful NATO-supported summer schools in crystallography which were held at Aarhus University. Outstanding lecturers from around the world aroused great interest in the latest developments within crystallography, and the schools paved the way for many Danish students to pursue further studies in leading crystallographic research groups.
In his private life, Svend Erik was married to Finnish-born Dorrit for 73 years. Both were excellent skiers, and even in their late eighties they could often be found on European alpine slopes.
Svend Erik Rasmussen leaves behind an impressive scientific legacy, and we remember with sadness a curious, courageous, and dedicated researcher and teacher of chemistry and crystallography, an outstanding academic leader, a person of deep loyalty to others, and his tireless commitment to Aarhus University.
Honour to the memory of Svend Erik Rasmussen.
The 6th National Crystallography Meeting was held on 17–19 May 2026 in Giresun, Türkiye, under the hosting of Giresun University and in collaboration with the Turkish National Crystallographic Association. The meeting brought together researchers working in various branches of crystallography, structural science, materials characterization, and related interdisciplinary fields.
The opening ceremony included speeches by Prof. Dr. Canan Kazak, President of the Turkish National Crystallographic Association, and Prof. Dr. Santiago Garcia-Granda, President of the International Union of Crystallography (IUCr). Prof. Dr. Güven Özdem, Vice Rector of Giresun University, also attended the ceremony. In addition, a message from Prof. Dr. Dinçer Ülkü, one of the pioneering scientists contributing to the development of crystallography in Türkiye, was shared with the participants.
The scientific programme focused on current developments in crystallographic research and covered topics including macromolecular crystallography, molecular structures and properties, powder diffraction applications, materials science, and fundamental crystallographic concepts.Including interesting discussions on the research actions under the TÜBİTAK programs. Oral and poster presentations highlighted recent experimental, computational, and methodological advances in the field.
The meeting hosted distinguished invited speakers from internationally recognized institutions. These included Assoc. Prof. Dr. Cengiz Arıcı (TÜBİTAK, Türkiye), Prof. Dr. William Clegg (Newcastle University, United Kingdom), Prof. Dr. Santiago Garcia-Granda (University of Oviedo, Spain), Dr. Mustafa Fatih Genişel and Dr. Santanu Pathak from SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East, Jordan), Prof. Dr. Michael Richard Probert (Newcastle University, United Kingdom), Prof. Dr. Zehra Sayers (Sabancı University, Türkiye), and Prof. Dr. Veysel Turan Yılmaz (Karadeniz Technical University, Türkiye).
The participation of researchers from different countries and institutions provided an important platform for scientific exchange and interdisciplinary collaboration. Particularly interesting to know the progress in the implementation of new lines, instruments and experimental facilities in the SESAME synchrotron. Discussions throughout the meeting emphasized the increasing role of crystallographic methods in structural chemistry, materials science, biology, and advanced characterization techniques.
In addition to the scientific sessions, participants had the opportunity to enjoy the most traditional music and dance performances, put on by local groups, at an unforgettable opening ceremony, to enjoy the abundance of hazelnuts produced in this region of Türkiye, and finally to experience the natural and cultural heritage of the Black Sea region through the social programme organized during the meeting.
The organizers expressed their sincere appreciation to all invited speakers, participants, supporting institutions, students, and organizing committee members whose contributions ensured the scientific success of the meeting.
Benedikt Kienle, a student at Lancaster Country Day School, received first place in Chemistry at the Regeneron International Science and Engineering Fair (ISEF), the world's largest pre-college science competition. His project, "New Green Chemistry Iridium Catalysts", was conducted under the mentorship of Dr. R. Edward Rajaseelan at Millersville University. Benedikt's research was also featured in IUCrData, with one of his crystal structures selected for the journal cover. Reflecting on his ISEF experience, he shared the following thoughts.
As a high school student, I was told many times that I should pursue my passion so that I would never have to work a day in my life. This year’s experience, both at ISEF and in preparation for it, made me realize that it isn't just a saying but the truth being able to see the amazingly talented and smart kids around me was just a joy. From difficult math theorems to humanoid legs, the week at ISEF made me feel so positive about the future of science, and the people who are in control of it are incredibly capable and fun to be around. The biggest takeaway for me, however, was that it is more important to do these things for science itself than for the prizes and awards that come with it. Having my X-Ray crystal structures in general, and especially the publication was a huge encouragement in my research. Not only did it motivate me even more, but especially being on the cover was very beneficial to the project. Being able to display that honor on my poster is what gave it its final touch and played a big role in my success at ISEF. If you are passionate about your project and have fun doing what you do, not only will it not feel like work, but the awards will come, too.
In April 2026, Graz University of Technology and Anton Paar GmbH jointly hosted the fifth edition of the international SAXS & XRD excites Symposium, bringing together a global community of experts in X-ray structural analysis. With more than 140 participants from over 30 countries, the event once again proved to be a vibrant platform for multidisciplinary exchange between renowned scientists, early-career researchers, and industry professionals.
Over the course of the symposium, attendees engaged in intensive discussions on the latest scientific developments and emerging trends across a wide spectrum of X-ray-based techniques.
The focus was on techniques for investigating nanomaterials, as well as methods for analyzing thin films and surfaces. Other key topics included advanced X-ray methods for battery research and new approaches to studying amorphous materials.
Beyond the scientific program, participants toured Anton Paar’s headquarters in Graz and gathered for a joint conference dinner at the Sudhaus restaurant, creating further opportunities for informal exchange and networking.
The 2026 symposium emphasized the growing importance of small-angle X-ray scattering (SAXS) as a powerful tool for the characterization of complex materials. In collaboration with Graz University of Technology – which uses these methods extensively for research of nanostructured and crystalline materials – Anton Paar GmbH will continue to contribute to the advancement of X-ray structural analysis and the exploration of new application fields.
“X-ray diffraction is a significant growth market for Anton Paar, and our XRD portfolio remains a key area of investment,” says Dr. Christopher Fradler, Head of Business Unit Solutions at Anton Paar. “Although SAXS serves a smaller market, our 70 years of experience in the field and close customer relationships mean we remain committed to advancing our solutions for scientific customers.”
SAXS & XRD excites will return in 2028.
Contact Anton Paar for updates: [email protected]
www.anton-paar.com
The “International School on Fundamental Crystallography and Workshop on Rietveld Refinement Analysis” (ISFC-2026) was held at the Department of Physics & Astronomy, National Institute of Technology (NIT) Rourkela, India from 23rd to 28th February 2026. This was the 3rd event in India in which the Commission on Mathematical and Theoretical Crystallography (IUCr MaThCryst) was directly involved in the organization. The 1st one was organized on the topic “Symmetry relationships between crystal structures with application to structural phase transitions” at Indian Institute of Technology (Banaras Hindu University) (IIT, BHU), Banaras, India, during 27th to 31st October 2014. The 2nd school, titled “Fundamental Crystallography and Workshop on Structural Phase Transitions: A Satellite meeting of 24th IUCr Congress, 2017” (ISFCWSPT-2017) was held at the Department of Physics & Astronomy, National Institute of Technology (NIT) Rourkela, India from 30th August to 4th September 2017.
The school commenced with a brief inaugural session on 23rd February 2026 at 09:00 AM. During the session, the Director, Dean SRICCE, and Registrar of National Institute of Technology Rourkela welcomed the speakers and participants and provided an overview of the Institute. The Head of the Department of Physics & Astronomy, National Institute of Technology Rourkela, also presented a brief overview of the Department. Dr. Dillip K. Pradhan, Coordinator of the School, highlighted the objectives of the program and emphasized the importance of the School and workshop for the participants.
The main focus of the event was to provide an understanding of the fundamentals of crystallography and the implementation of Rietveld refinement analysis of powder diffraction data of functional materials such as ferroics and multiferroics. The scientific program was divided into two parts. The first part of the program was the School on Fundamental Crystallography, which included 14 lectures (25 hours) conducted during the first three and a half days. These lectures covered fundamental crystallographic topics starting from crystallographic symmetry and its application to two- and three-dimensional crystallographic point and space groups, symmetry relations between space groups including group-subgroup and group-supergroup relationships, crystal-structure descriptions and comparison. The second part focused on Rietveld Refinement Analysis and consisted of 10 lectures, including tutorials, hands-on training, and practical sessions, totaling 19 hours. The last two and a half days were devoted to discussions on reciprocal-space construction and diffraction, X-ray powder diffraction, theoretical basis as well as strategy of Rietveld refinement analysis. The lecture sessions were complemented by hands-on practical sessions on space groups descriptions in Volume A of International Tables for Crystallography and online training for determination of subgroups of space groups and their applications in crystal-structure relations and comparisons using Bilbao Crystallographic Server (freely available). The workshop on Rietveld refinement analysis was also based on intensive hands-on sessions using the computer programs of the Full Prof Suite (freely available).
All the lectures were taken by renowned experts in the field such as Prof. Massimo Nespolo, Université de Lorraine, Nancy, France, Prof. Mois Ilia Aroyo, Universidad del País Vasco, Bilbao, Spain (online), Prof. Juan Rodríguez-Carvajal, Institut Laue-Langevin, Grenoble, France, Prof. Claire V. Colin, Institut Néel - CNRS & UGA, Grenoble, France, Dr. Gemma de la Flor Martín, Karlsruhe Institute of Technology, Germany (online), Dr. Dillip K. Pradhan, National Institute of Technology Rourkela, Odisha, India, Dr. Ranjana R. Das, Government Autonomous College, Rourkela, Odisha, India. The tutorials, hands-on training, and practical sessions were conducted by Dr. Dillip K. Pradhan, Dr. Ranjana R. Das, Dr. Anupam Mishra, National Institute of Technology Rourkela, Odisha, India and Dr. Anusree V. K., R Sankar Memorial SNDP Yogam Arts & Science College, Koyilandy, Kerala, India.
The organizers plan to host another Mathematical and Theoretical Crystallography School and workshop on some more advanced aspect of Crystallography in India in near future.
CommDat is the IUCr standing committee that provides a coordinating and advisory role regarding data. It follows up on the work of the IUCr Diffraction Data Deposition Working Group (DDDWG, 2011–2017), which explored the deposition of primary diffraction images and mechanisms enabling their retrieval by others for purposes such as reanalysis, software and methods development, validation and review. This working group recommended that authors should provide a permanent and prominent link to the raw data sets underpinning their article, thus promoting open science.
CommDat took up a prominent role to integrate data-related issues into the programme of the IUCr 2026 congress in Calgary with great enthusiasm through sponsoring, co-sponsoring or supporting a range of Commissions. As a result, a dominant theme running through the conference is ‘data’ - from management & format, through open science to application of AI/ML.
Before the Congress even gets underway, there is the chance to attend an innovative summer school! The inaugural ‘AI in Crystallography’ Summer School is being held close to Calgary in nearby Lethbridge (August 8th-11th). Its format is a mixture of informative lectures, supplemented by hands-on exercises that will cover everything from fundamental AI, through data preparation to training and applying models.
There are a record number of workshops at this Congress – many of them relating to data. In particular, CommDat is organising a 1-day workshop entitled From Open Data to Global Open Science (Workshop 012). Is there a multitude of open science initiatives, or is open science a clearly structured landscape? This is your chance to learn more! Open Science aims at making research results and the underlying data openly available to the larger community via data sharing. This requires the data to adhere to the Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. This workshop will explore the fact that while Open Data systems are developing at national and regional levels, there is a need for more coordination at the disciplinary (ie crystallography!) level.
Furthermore, some of the conference microsymposia address Open Science issues and the FAIR data principles. For open science to thrive, open data needs to be produced, managed, and made available in a coordinated manner, which is driving a growing need to present standardised data and metadata accurately, following modern best practices and adhering to the FAIR principles. These topics will be covered in MS027: Coordinated Efforts Towards Open Data for Global Open Science, MS045: Open data, standards, and repositories for small- and wide-angle X-ray and neutron scattering data in the era of big data and AI advancements.
There are also a range of other data-related workshops and microsymposia to attend, including Workshop 007: Enhancing PDB Deposition and Validation, Workshop 009: Reproducibility in Practice, Workshop 016: Mastering the CSD; Enabling PDB deposition of Integrative/Hybrid methods structures, Workshop 019: DIALS for processing diffraction images, MS076: Integrative Structural Chemistry and Biology: The Power of Combining Data, MS059: Using crystallographic databases for data exploration, MS-058: Best practices for X-ray, neutron and electron data processing and reuse, MS-059: Using crystallographic databases for data exploration and exploitation.
The CommDat Keynote, entitled ‘Coordinated efforts towards open data for global open science’ will be given by Bridget Murphy from Kiel University (also DESY and DAPHNE4NFDI). In addition, there is a Keynote by Suzanna Ward from CCDC entitled ‘The Cambridge Structural Database: A catalyst for solving scientific challenges’.
The importance of Artificial Intelligence and Machine Learning techniques in crystallography has a longer history than one might think. A comprehensive overview is provided in two recent IUCr journals virtual issues: “Machine learning in crystallography and Structural Science” by Simon Billinge and Thomas Proffen (2024), and “Artificial neural networks: application in X-ray photon science and crystallography” by Tomas Ekeberg (2024). A more global application of AI and ML can only be achieved if data are archived and made available in a FAIR manner. Think of AlphaFold2 (Jumper et al., 2021), which is based on over 100 thousand unique protein structures available in the PDB at that time. Learn about the latest developments in: MS-013 Big data and crystallography, MS-050 Machine learning in low-resolution crystallographic computing, MS-102 Large-scale structure determination initiatives in the era of AI and ML, MS-124 Applications of ML and AI in biological small-angle scattering, MS-130 AI & ML in crystallography and scattering, MS-134 Crystallography and X-ray Absorption Spectroscopy Machine Learning methods for the development of materials. Cutting-edge developments in data-driven approaches for X-ray and neutron science, with a focus on innovations in data acquisition, processing, and analysis, will be addressed in MS128: Data-Driven Science: Current Status and Outlook.
Crystallography has a long data-sharing tradition when it comes to our derived models and structure factors, as well as pioneering validation methods like checkCIF and PDB validation reports. Significant progress has been made in sharing raw diffraction data and deploying checkCIF for raw data tools (see below at Raw Data Letters). The latest advancements are revealed in: MS-012: Next-generation validation metrics for macromolecular structures, MS-040: Advanced data analysis and refinement for electron diffraction data, MS-098: Data quality and error analysis for diffuse scattering.
Fully in focus with the data sharing tradition, our peer-reviewed open-access data publication IUCrData, has launched a new section – Raw Data Letters, a collaborative innovation between IUCr Journals and CommDat. Quoting from the editorial: the new section will publish short descriptions of crystallographic raw data sets from X-ray, neutron or electron diffraction experiments, in the biological, chemical, materials science or physics fields, and provide a persistent link to the location of the raw data…..Raw Data Letters support Open Science policies: no research data should be lost, but should be made available to the research community according to the FAIR principles, for which the correctness and completeness of the metadata are crucial, and these will be central to the reviewing process. A publication in Raw Data Letters describes interesting features of the data that were observed but not accounted for in an already published structure, or even for an unsolvable structure that would challenge method developers. In the paper, a persistent link (DOI) must be provided to the location of the raw data in a permanent repository (see Figure for the front page of the first Raw Data Letter showing the links in the grey box). However, raw data come in many different data formats and varying metadata quality. To ensure reusability, metadata should be accurate and complete, and at least sufficient. For single-crystal data, a list of core metadata has been prescribed (Kroon-Batenburg et al., 2022), and their inclusion is a key requirement for correct reprocessing of the data, even more so if automation is a concern. This list is a superset of the NeXus/HDF5 NxMx Gold Standard that was developed by Bernstein et al. (2020). Metadata is captured in imgCIF format (Bernstein & Hammersley, 2005), which is well known to the community via its CBF variant, and already includes the appropriate data names for the core metadata list. To support this method of publication, the imgCIF_creator tool (Kluyver et al, 2026) has been developed to read a collection of raw data files, produce a description of the associated metadata, including references to the locations of the raw data files, and write these in an ‘imgCIF’ file. The imgCIF file provides data in CIF format, which is both machine-readable and human-readable, with a comprehensive set of tags (defined in the imgCIF dictionary) for describing detector geometries and other experimental parameters, thus facilitating FAIR ‘re-usability’. A checkCIF for raw data (Hester, 2026) has been established to validate the completeness and correctness of the metadata. The workflow of the IUCrData submission system, with imgCIF_Creator and checkCIF for raw data tools, is show in the Figure. The archived raw data, imgCIF metadata, and ultimately the published Raw Data Letter, are linked via DOIs.
Recently, it seems that everywhere we look, both in our professional and personal lives, data is the latest trend and a currency that drives everything we do. Clearly, this is also the case in the IUCr at our Congress and with our latest journal! However, let us not forget that over a century ago, one of our founding fathers was already thinking in this way: in his 1913 foundational article, Lawrence Bragg (W L Bragg 1913) published his raw diffraction images, Laue diffraction photos from his alkali halide crystals, with which he showed how he deduced the “first crystal structure”!
Bernstein, H. J., Förster, A., Bhowmick, A., Brewster, A. S., Brockhauser, S., Gelisio, L., Hall, D. R., Leonarski, F., Mariani, V., Santoni, G., Vonrhein, C. & Winter, G. (2020). Gold Standard for macromolecular crystallography diffraction data. IUCrJ, 7, 784–792. https://doi.org/10.1107/S2052252520008672
Bernstein, H. J. & Hammersley, A. P. (2005). Specification of the Crystallographic Binary File (CBF/imgCIF). In S. R. Hall & B. McMahon (eds.), International Tables for Crystallography, Volume G: Definition and exchange of crystallographic data, pp. 37–43. Chester: International Union of Crystallography.
Billinge, S. J. L. & Proffen, T. (2024). Machine learning in crystallography and structural science. Acta Crystallographica Section A, 80, 139–145. https://doi.org/10.1107/S2053273324000172
Bragg, W. L. (1913). The structure of some crystals as indicated by their diffraction of X-rays. Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character, 89, 248–277, Fig. 3. https://doi.org/10.1098/rspa.1913.0083
Ekeberg, T. (2024). Introduction to the virtual collection of papers on Artificial neural networks: applications in X-ray photon science and crystallography. Journal of Applied Crystallography, 57, 1–2. https://doi.org/10.1107/S1600576723010476
Hester, J. R. (2026). imgCIFHandler.jl. GitHub repository. https://github.com/jamesrhester/imgCIFHandler.jl
Jumper, J., Evans, R., Pritzel, A., Green, T., Figurnov, M., Ronneberger, O., Tunyasuvunakool, K., Bates, R., Žídek, A., Potapenko, A., Bridgland, A., Meyer, C., Kohl, S. A. A., Ballard, A. J., Cowie, A., Romera-Paredes, B., Nikolov, S., Jain, R., Adler, J., Back, T., Petersen, S., Reiman, D., Clancy, E., Zielinski, M., Steinegger, M., Pacholska, M., Berghammer, T., Bodenstein, S., Silver, D., Vinyals, O., Senior, A. W., Kavukcuoglu, K., Kohli, P. & Hassabis, D. (2021). Highly accurate protein structure prediction with AlphaFold. Nature, 596, 583–589. https://doi.org/10.1038/s41586-021-03819-2
Kluyver, T., Dall'Antonia, F., Hester, J. R. & Kroon-Batenburg, L. M. J. (2026). MC-ReDD: Metadata Capture and validation for Re-use of raw Diffraction Data. OSCARS project report. https://oscars-project.eu/projects/mc-redd-metadata-capture-and-validation-re-use-raw-diffraction-data
Kroon-Batenburg, L. M. J., Helliwell, J. R. & Hester, J. R. (2022). IUCrData launches Raw Data Letters. IUCrData, 7, x220821. https://doi.org/10.1107/S2414314622008215
wwPDB Consortium (2019). Protein Data Bank: the single global archive for 3D macromolecular structure data. Nucleic Acids Research, 47, D520–D528. https://doi.org/10.1093/nar/gky949
Wolfram Saenger was born on 23 April 1939 in Frankfurt-Höchst, Germany. His father was an industrial chemist, and the family relocated several times during his childhood. Saenger spent his school years in Grenzach on the Rhine opposite Basel. From 1958 to 1964 he studied chemistry at the Technische Hochschule Darmstadt and at the University of Heidelberg. In 1964 he obtained his Diplom at TH Darmstadt. One year later, he completed his doctoral degree (Dr.-Ing.) under the supervision of Friedrich Cramer, studying rapid kinetics of cyclodextrin inclusion complexes in the laboratory of Manfred Eigen in Göttingen (Cramer et al., 1967).
From 1965 to 1967 Saenger pursued postdoctoral research at Harvard University, working with Robert B. Woodward and Jack Z. Gougoutas, where he learned X-ray crystallographic methods for small organic molecules (Simon et al., 1967). During this period he also collaborated with Elias J. Corey, including work on the symmetric synthesis of α-amino acids that appeared in 1970 (Corey et al., 1970).
Saenger returned to Germany in 1967 to head the X-ray crystallography group in the Department of Chemistry at the Max Planck Institute for Experimental Medicine in Göttingen, directed by Friedrich Cramer. He completed his habilitation at the University of Göttingen in 1971. After receiving several offers in the late 1970s, he accepted a professorship in 1981 at the Institute of Crystallography of Freie University of Berlin, where he built an internationally renowned centre for structural biology.
Saenger's early scientific interests focused on host–guest chemistry, particularly the structures and inclusion complexes of cyclodextrins and polyethers (Manor & Saenger, 1972; Hingerty & Saenger, 1975; Noltemeyer & Saenger, 1976; Gessler et al., 1994). The subtle and highly specific interactions between host and guest molecules provided model systems for understanding molecular recognition in biology. These studies naturally led him to the central role of hydrogen bonding in biomolecular structure. In cyclodextrin structures, he recognized the presence of three-dimensional hydrogen-bonding networks with circular arrangements of four or more water molecules (Saenger, 1979) and the cooperative flip of H atoms in equilibrium between two states: O—H⋯O ⇌ O⋯H—O (Saenger et al., 1982). Together with William N. Hunter and Olga Kennard, he recognized the importance of hydrogen bonding and hydration on the conformation of DNA (Saenger et al., 1986). His work in this area culminated in the influential monograph Hydrogen Bonding in Biological Structures, written together with George A. Jeffrey, which remains a foundational reference (Jeffrey & Saenger, 1991).
Cyclodextrins and other oligosaccharide and polysaccharides remained a recurring theme in Saenger's research (Hinrichs et al., 1987). Among his notable achievements was the structural characterization of a cyclic oligoglucose consisting of 26 monomer units (Gessler et al., 1999). Yet from early in his career he was equally fascinated by nucleic acids and their building blocks (Suck et al., 1972; Saenger, 1973; Saenger & Suck, 1973; Saenger et al., 1977). As early as 1968 he reported single crystals of phenylalanine-specific transfer RNA (Cramer et al., 1968), placing him and Friedrich Cramer in the international race to determine the first tRNA structure. Saenger's work on modified nucleic acid bases, abundant in tRNA, included landmark studies such as the structure of the base pair between 1-methyl-4-thiouracil and 9-methyladenine published in Nature in 1970 (Saenger & Suck, 1970).
Beyond experimental crystallography, Saenger increasingly integrated theoretical approaches into his studies of nucleosides and nucleotides, collaborating with leading theoreticians including Bogdan Lesyng and Camillo A. Tosi (Banerjee et al., 1978). His deep and comprehensive knowledge of nucleic acid structure was synthesized in his widely acclaimed book Principles of Nucleic Acid Structure (Saenger, 1983), which became a standard reference for students and researchers alike.
During his later years in Göttingen and especially after moving to Berlin, Saenger expanded his work decisively into protein crystallography. The first protein structures determined in his laboratory was that of α-cobratoxin (Walkinshaw et al., 1980), whose interaction with the nicotinic acetylcholine receptor provided important insights into receptor binding. Soon afterwards, his group solved the structure of the enzyme ribonuclease T1 (Heinemann & Saenger, 1982), initiating a long-standing programme combining crystallography with spectroscopy, mutagenesis and computational modelling to explore enzyme function and stability.
In Berlin, Saenger's laboratory investigated a wide array of biologically important macromolecules. Central among these were proteins interacting with carbohydrates (Holzenburg et al., 1987) and protein–nucleic acid complexes, including the factor for inversion stimulation (FIS; Kostrewa et al., 1991), the tetracycline repressor (TetR; Hinrichs et al., 1994) and DNA methyltransferases involved in DNA repair and restriction–modification systems (Labahn et al., 1994; Schluckebier et al., 1997). These studies significantly advanced the structural understanding of gene regulation and DNA recognition.
A particularly ambitious line of research addressed large membrane-protein complexes. Saenger and his collaborators determined important structures of cyanobacterial photosystems I (Krauss et al., 1993, 1996; Jordan et al., 2001) and II (Zouni et al., 2001; Loll et al., 2005; Yano et al., 2006; Guskov et al., 2009), among the most challenging targets in structural biology at the time. Later projects extended to proteins of the human immune system, notably major histocompatibility complex (MHC) molecules that present antigen-derived peptides to T cells and thereby initiate cellular immune responses (Menssen et al., 1999; Uchanska-Ziegler et al., 2012).
Throughout his career Saenger was known for tackling problems at the limits of technical feasibility. Membrane proteins and large multi-subunit complexes, often considered among the most difficult targets in crystallography, featured prominently in his research. His ability to sustain such ambitious projects over many years reflected both scientific determination and a remarkable capacity to integrate diverse experimental and theoretical approaches.
Saenger's scientific productivity was extraordinary. He authored more than 600 scientific publications, many in leading journals, as well as several influential books and review articles. His work was widely recognized through numerous honours. He was elected a member of the European Molecular Biology Organization (EMBO) in 1984, received the Gottfried Wilhelm Leibniz Prize in 1988 and the Alexander von Humboldt Research Award in 1989, and became a member of the Berlin-Brandenburg Academy of Sciences and Humanities in 1994. In 2004 he received the Carl-Hermann Medal of the German Association of Crystallography for his life's work.
Saenger was head of the West German Arbeitsgemeinschaft Kristallographie and played an important role in the unification of crystallographers and the establishment of the German Crystallographic Society in 1991 after German reunification. He served as co-editor of Acta Crystallographica Section D and as chairperson of the Commission on Biological Macromolecules of the IUCr from 1996 to 1999. An important topic at that time was the deposition and release of the coordinates and diffraction data of macromolecular structures (Baker & Saenger, 1999). Wolfram Saenger played a leading role in establishing the Protein Structure Factory, a large-scale structural genomics initiative based in Berlin (Heinemann et al., 2000). The project led to the development of key research infrastructure, including synchrotron beamlines at BESSY II (Helmholtz Zentrum Berlin).
Equally important was Saenger's role as a mentor. Generations of students and postdoctoral researchers benefited from the intellectual freedom and generous support he offered. Many of his former group members have gone on to leading positions in academia and industry, forming what colleagues often described as a distinctive `Saenger school' of structural biology.
Wolfram Saenger believed that scientific research should be pursued with intellectual honesty, curiosity and uncompromising standards of quality. His work exemplified a rare breadth of interests, spanning small molecules, nucleic acids, proteins and large macromolecular assemblies, combined with a deep commitment to fundamental understanding. His contributions have left an enduring imprint on crystallography and structural biology, and his influence will continue to be felt through the many scientists that he trained and inspired.
This article was originally published in Acta Cryst. (2026). D82, 571–573.
Baker, E. N. & Saenger, W. (1999). Acta Cryst. D55, 2–3.
Cramer, F., Saenger, W. & Spatz, H.-C. (1967). J. Am. Chem. Soc. 89, 14–20.
Heinemann, U. & Saenger, W. (1982). Nature 299, 27–31.
Hingerty, B. & Saenger, W. (1975). Nature 255, 396–397.
Loll, B., Kern, J., Saenger, W., Zouni, A. & Biesiadka, J. (2005). Nature 438, 1040–1044.
Manor, P. C. & Saenger, W. (1972). Nature 237, 392–393.
Menssen, R., Orth, P., Ziegler, A. & Saenger, W. (1999). J. Mol. Biol. 285, 645–653.
Noltemeyer, M. & Saenger, W. (1976). Nature 259, 629–632.
Saenger, W. (1973). Angew. Chem. Int. Ed. Engl. 12, 591–601.
Saenger, W. (1979). Nature 279, 343–344.
Saenger, W. (1983). Principles of Nucleic Acid Structure. New York: Springer-Verlag. GoogleScholar
Saenger, W., Betzel, C., Hingerty, B. & Brown, G. M. (1982). Nature 296, 581–583.
Saenger, W., Hunter, W. N. & Kennard, O. (1986). Nature 324, 385–388.
Saenger, W., Reddy, B. S., Mühlegger, K. & Weimann, G. (1977). Nature 267, 225–229.
Saenger, W. & Suck, D. (1970). Nature 227, 1046–1047.
Saenger, W. & Suck, D. (1973). Nature 242, 610–612.
Simon, M. S., Rogers, J. B., Saenger, W. & Gougoutas, J. Z. (1967). J. Am. Chem. Soc. 89, 5838–5844.
Suck, D., Saenger, W. & VorbrÜggen, H. (1972). Nature 235, 333–334.
Walkinshaw, M. D., Saenger, W. & Maelicke, A. (1980). Proc. Natl Acad. Sci. USA 77, 2400–2404.
The IUCr Newsletter (ISSN 1067-0696; coden IUC-NEB) is published electronically by the International Union of Crystallography. Feature articles, meeting announcements and reports, information on research or other items of potential interest to crystallographers may be submitted to the Editors at any time. Items will be selected for publication on the basis of suitability, content, style, timeliness and appeal.
Copyright © - All Rights Reserved - International Union of Crystallography
