Welcome to the

International Union of Crystallography

The IUCr is an International Scientific Union. Its objectives are to promote international cooperation in crystallography and to contribute to all aspects of crystallography, to promote international publication of crystallographic research, to facilitate standardization of methods, units, nomenclatures and symbols, and to form a focus for the relations of crystallography to other sciences.


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In early May, during a Workshop on Crystallography and X-ray Diffraction, our Guatemalan colleagues founded the Guatemalan Association of Crystallography as a first step to becoming part of the IUCr. Sadly, those same colleagues are now struggling to deal with the after effects of the eruption of the Fuego volcano that claimed numerous lives. One way to provide financial support to the victims of the eruption would be via a site such as https://www.globalgiving.org/projects/guatemala-volcano-relief-fund/.
Posted 15 Jun 2018 

research news

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Hydrophobic dipeptides: the final piece in the puzzle

The results from ab initio structure prediction programs have demonstrated that any organic molecule has the potential to interrelate with its siblings in a number of different ways, the observed crystal structure representing an energy minimum where the contributions from various types of intermolecular interactions have been carefully balanced. Systematic investigations of molecules that share one important moiety/feature provide valuable experimental data for the understanding of this balance and for rationalizing important trends, even among other sets of compounds. Amino acids constitute an attractive group for such a survey, with a common polar head and a variable side chain. Crystal structures of more than 120 regular, acyclic amino acids have been published in the past, meaning that the 20 proteinogenic amino acids represent but a minor fraction of the experimental material. If these amino acids are used, however, to construct dipeptides, they alone leave 20 x 20 = 400 different options. As of June 2018, crystal structures are only available for 104 of them.

[Hydrophobic dipeptides]Hydrophobic dipeptides is a subgroup of particular interest. These are based on combinations of the five non-polar amino acids alanine (Ala), valine (Val), isoleucine (Ile), leucine (Leu) and phenylalanine (Phe) only, meaning that hydrogen bonds are essentially limited to connecting the constant parts of the molecules, i.e. the peptide main chains. Accordingly, any change in crystal structure upon amino acid substitution is due to the side chain.

The crystal structure of Val-Leu acetonitrile solvate presented in Görbitz (2018). Acta Cryst. B74, 311-318 is the 25th and last missing piece in the 5 x 5 puzzle of hydrophobic dipeptide structures. This “completion event” is used here as an opportunity to review their crystal packing arrangements and hydrogen-bonding pattern preferences, the associated peptide conformations and the sometimes unexpected impact a seemingly modest amino acid substitution can have not only on the crystal structure but also on the propensity to include co-crystallized solvent molecules.

Carl Henrik Görbitz
Department of Chemistry, University of Oslo, Norway
Posted 19 Jun 2018


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Richard Henderson receives royal recognition

IUCrJ Editorial Board Member Richard Henderson (MRC LMB, Cambridge, UK) has been made a Companion of Honour in Queen Elizabeth II's 2018 Birthday Honours list for services to electron microscopy of biological molecules. The order is a special award held by only 65 people at any one time.

Desiraju and Henderson

Richard Henderson (right) with Gautam Desiraju, LOC Chair, at IUCr2017.

The Editor-in-Chief of IUCr Journals, Samar Hasnain, congratulated Richard on behalf of the editorial management board: "Richard deserves this special recognition as he has served the community over a long period influencing younger and senior colleagues alike with his infectious enthusiasm and passion for science. I and the Union are grateful for his tremendous hard work in helping to make cryo-electron microscopy [cryoEM] one of the main features of its journals, particularly IUCrJ, as well as the IUCr Congress held in Hyderabad last year."

In 2017, Richard shared the Nobel Prize in Chemistry for developing cryoEM for the high-resolution structure determination of biomolecules in solution, and won the IUCr Gjønnes Medal in Electron Crystallography along with Nigel Unwin (http://www.iucr.org/news/newsletter/volume-25/number-2/chemistry-nobel-prize).

More information about the Order of the Companions of Honour and Richard's career can be found at https://www2.mrc-lmb.cam.ac.uk/richard-henderson-made-companion-of-honour/.

Posted 12 Jun 2018 

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Advanced neutron scattering instrumentation

[neutron scattering special issue]Neutron scattering facilities are called to address an ever-expanding mission in the investigation, development and use of a broad range of materials: from investigating cultural heritage artifacts to advanced bio-materials, from studies of phase transitions and quantum matter to advanced engineering composites for aircraft. This breadth of applications, together with the complex problems they present for making scientific and technical progress, are key drivers for new advanced neutron sources and novel instrumentation that covers an enormously broad scale in both time and space.

These challenges must be met by neutron user facilities within a rapidly changing landscape, and there are significant investments under way in both neutron sources and instrumentation. Some of these developments are highlighted within a new virtual special issue of Journal of Applied Crystallography. Europe is constructing the European Spallation Source (ESS), an investment of over two billion USD that is rapidly rising from the ground in Lund, Sweden; the US Department of Energy is investing in the Spallation Neutron Source (SNS) to double its proton beam power on target from 1.4 to 2.8 MW. Both the spallation source at JPARC, Japan, and the SNS are advancing plans for additional target stations. The Institut Laue–Langevin (ILL) is currently executing phase one of its Endurance instrument upgrade program. Both ANSTO’s Australian Centre for Neutron Scattering (ACNS) in Sydney, Australia, and the Maier-Leibnitz Zentrum (MLZ) in Munich, Germany, are making significant investments in instrumentation technology and instruments to meet rising user demands.

Within these exciting developments, this special issue on advanced neutron scattering instrumentation highlights some of the innovative advances in neutron scattering instrumentation at facilities around the world that address a broad scientific and industrial scope of applications. The special issue provides us with an opportunity to take a glimpse on a global scale at some of the exciting developments in source and instrument suite design, high-performance instrumentation, and software. These developments are enabling new opportunities for science discovery through technologies such as detectors, sample environments and data acquisition advances.

This is an edited version of the full foreword to the special issue [Argyriou & Allen (2018). J. Appl. Cryst. 51, 567-569; https://doi.org/10.1107/S1600576718007987].
Posted 04 Jun 2018

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Weak interactions in crystals: an integrated approach

[weak interactions cover]Weak interactions have been gaining in importance and interest over the last 20 years owing to their applicability and usefulness in a wide range of scientific disciplines. They are essential in the formation of inclusion compounds, in the self-assembly of host–guest molecular complexes and in the study of polymorphism, co-crystals, phase transitions and charge density.

The May 2018 issue of Acta Crystallographica Section E Crystallographic Communications, "Weak interactions in crystals: an integrated approach", explores the fundamental role of detailed structural analysis in understanding weak interactions in the solid state. An Editorial by Chiara Massera and Helen Stoeckli-Evans introduces this special issue and is followed by a general review by Andrei Batsanov, which highlights the history, state-of-the-art and future developments of this field. The articles comprise six Research Communications on molecular salts, organic compounds and host–guest and coordination complexes, in which the weak interactions reported have in many cases been analysed by a combination of crystallographic analysis and theoretical techniques, showing the importance of an integrated approach. The role of different experimental set ups and refinement strategies has been highlighted in an Application Note.

Acta E has long been a benchmark for high-quality crystallographic data and structural discussions within the landscape of chemical scientific publications. The rigorous editing and reviewing of the papers, combined with the speed of publication and the open-access editorial policy, makes the journal easily accessible to a very broad audience, encouraging the authors to place their results in a larger scientific context. This is the first special issue that Acta E has produced and heralds an expansion of the journal's chemical content to highlight hot and consolidated topics through application notes, themed issues and reviews.

Posted 01 May 2018


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Journal of Applied Crystallography: the first 50 years and beyond


The first issue of Journal of Applied Crystallography appeared in April 1968. So, with the April 2018 issue we celebrate its 50th birthday. Although the name suggests a focus on crystallography, Journal of Applied Crystallography has served a broad interdisciplinary readership ever since its conception, and the very first paper published was a paper on electron microscopy [Heidenreich, Hess & Ban (1968). J. Appl. Cryst. 1, 1-19; https://doi.org/10.1107/S0021889868004930]. Before long, Journal of Applied Crystallography had developed its reputation as a reliable forum for rigorously reviewed papers across the whole breadth of applied crystallography, with a strong presence of research combining crystallographic methods with other measurements.

Through the hard work of all our editors and editorial staff, Journal of Applied Crystallography continues to be recognized as a place to publish significant research featuring applied crystallography and crystallography applied in an interdisciplinary setting, as well as studies on noncrystalline materials. Our mix of published papers continues to include work associated with high-brilliance synchrotron and free-electron laser X-ray sources, despite many other avenues (both IUCr and non-IUCr) being available for reporting such research. We retain a strong presence in neutron scattering applications, and we continue to encourage industrial applications of crystallography. Finally, our founding Editor, André Guinier, would be very pleased to see that the prominence of small-angle scattering, the field he founded, has not diminished in these pages over the years.

We express our appreciation for all the readers, authors, reviewers, editors and technical staff who have made the journal what it has become over the past 50 years. And we look forward to working with the Journal of Applied Crystallography community to make the next 50 years even better.

This is an edited version of the full editorial celebrating the journal's 50th anniversary [Allen, Hajdu & McIntyre (2018). J. Appl. Cryst. 51, 233-234; https://doi.org/10.1107/S1600576718004478]. To mark this special occasion, the very first article and the top cited articles from the past 50 years are currently free to read here.
Posted 05 Apr 2018