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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IUCrJ celebrates its first year of publication

me0562thumbnailTo coincide with the International Year of Crystallography (IYCr2014), IUCr Journals launched the comprehensive open-access journal IUCrJ in January 2014. The journal has had an excellent first year, and has already started to establish itself within the wider scientific communities that use results obtained from diffraction methods. All the indications are good in terms of the journal making a strong impact in attracting high-quality science papers of wide scientific significance from these communities. First impressions from authors, readers, referees and commentators are very positive with a number of papers receiving high downloads in line with high-impact publications.

In addition to providing high-impact high-profile publications, IUCrJ also aims to provide fast publication for authors. Submissions undergo preliminary screening by a panel consisting of the five Main Editors (Ted Baker, Richard Catlow, Gautam Desiraju, Sine Larsen, John Spence) and the Editor-in-Chief (Samar Hasnain), and this has helped to provide a rapid and efficient review process. Preliminary screening is generally complete within 72 hours, and any articles that do not meet the journal's requirement for broad scientific significance are usually transferred, with the agreement of the authors, to one of our other journals. Such transfers are seamless and do not require any further work by the authors.

The six issues of IUCrJ published in 2014 have featured papers from a wide variety of areas including biology, chemistry, crystal engineering, materials, physics and FELs. The number of articles submitted to the journal in its first year was 130; this was well ahead of our target of 100 articles. A total of 72 papers have been published with an average turnaround time of 14 weeks. A number of papers have been highlighted via an in-depth commentary in a manner similar to other comprehensive journals such as Nature and PNAS.

IUCrJ has set out to become the natural home for reporting breakthroughs and `full' science reports ratherm140100coverimage than simply reporting a structure or how it was determined. We welcome your impressions of the first year of IUCrJ and ideas of measures we should collectively take for its widest acceptance by the broadest possible community. We feel that we have made an excellent start and have attracted many high-quality submissions in all of the areas we cover. To maintain this confident start we encourage continued pro-active engagement from the whole structural community in improving the rate of submission of high-quality papers across the board.

We want IUCrJ to become the leading journal for high-quality structure-based papers in the chemical and biological sciences. We remind these communities to consider IUCrJ as one of their first choice journals for their work that may have broader appeal. In addition, we will continue to work closely with physicists, material scientists, computational crystallographers and pioneering FEL scientists to ensure that IUCrJ is able to meet the expectations of these communities.

Samar Hasnain
Editor-in-Chief, IUCr Journals

This is an excerpt taken from the full editorial which can be found at http://journals.iucr.org/m/issues/2015/01/00/me0562/index.html

 

Posted 19 Dec 2014 

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The wingspan of mathematical crystallography

mathematical crystallographyA special virtual issue of Acta Crystallographica Section A on mathematical crystallography is now available.

This virtual issue http://journals.iucr.org/special_issues/2014/MathCryst/ collects together a series of articles originally published in the journal between March and July 2014.

Crystallography is a natural area for the collaboration of physical science and mathematics. Much of 'mathematical crystallography' arose during the 19th century from the work of mathematicians, mineralogists, physicists and chemists. It was, and is again, a genuinely interdisciplinary field. Moreover, the growing demand for materials in general, and crystals in particular, will entail a growing need for an expanded mathematical toolkit. Whatever the advances in packaging software for non-mathematically inclined users, mastery of a mathematical toolkit requires a good understanding of the mathematics.

Such considerations led to the formation of a MaThCryst 'workgroup' in 2002, which the 20th IUCr Congress in Florence transformed into the Commission on Mathematical and Theoretical Crystallography in August 2005. The MaThCryst workgroup had organized a school in Nancy that June, and from that event came a special issue on Mathematical Crystallography in Acta Crystallographica Section A in March 2006 (Volume 62, Part 2). Since then, the MaThCryst Commission has organized and participated in many activities all over the world. In particular the lack of a solid education in fundamental crystallography among chemists, crystallographers, physicists and other participants has prompted the Commission to develop other itinerant schools, which are becoming a tradition.

MaThCryst plans four activities this year. For details, see the MaThCryst website at http://www.crystallography.fr/mathcryst

The Commission also organizes satellite conferences and workshops all over the world. A recent and fruitful cooperation with US mathematicians has resulted in crystallographic special sessions at sectional meetings of the American Mathematical Society and specialized conferences of the Society for Industrial and Applied Mathematics.

Perhaps befitting this digital age, this is a virtual issue, spanning three regular issues, but all appearing during the International Year of Crystallography. The result is a wide but necessarily incomplete selection from the panorama of research activities. We are confident that this virtual issue demonstrates the actuality and the importance of mathematical crystallography for every researcher interested in the periodic structure of matter, whatever the dimension and geometry.

M. Nespolo and G.McColm
Guest Editors 

This is an excerpt taken from the full editorial which can be found at http://journals.iucr.org/special_issues/2014/MathCryst/

Posted 16 Dec 2014 

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Leibniz Prize for DESY scientist Henry Chapman

hchapmanDESY scientist and co-editor of IUCrJ, Professor Henry Chapman will be awarded one of the prestigious Gottfried Wilhelm Leibniz Prizes 2015 by the German research foundation Deutsche Forschungsgemeinschaft (DFG), the DFG announced on 10 December 2014 in Bonn. This important research award in Germany honours outstanding scientists. Henry Chapman receives the 2.5 Million Euro prize for his pioneering work in the development of femtosecond crystallography. It allows to decode the structure of complex biomolecules in its natural environment at the atomic level with the help of X-ray lasers.

The atomic structure of biomolecules has an elementary influence on its function in the biological system. That is why scientists try very hard to decode these structures, e.g. to find approaches to produce new medication. In this connection crystallography plays a central role: when crystals are irradiated with X-ray light, they scatter the X-rays in a characteristic way. The resulting scattering image allows to calculate the structure of the building blocks of the crystal – in the case of a biomolecule crystal, this is the structure of its molecules.

Frequently, this structure analysis is carried out with the intensive X-ray light of large-scale synchrotron radiation sources such as PETRA III at DESY. Up until now, it has been possible to decode the structure of about 85,000 proteins. However, when using conventional synchrotron radiation sources, it is necessary to combine molecules to regular crystals in order to obtain a sufficiently intensive scattering image for structure calculation. This process is often very complex, sometimes impossible; moreover, the crystallisation rips the biomolecule out of its natural environment.

Novel free-electron X-ray lasers like the European XFEL, currently under construction in Hamburg, produce unprecedentedly brilliant and short X-ray flashes. Its light flashes with a length of only about some millionths of a billionth of a second will be more brilliant than today’s light sources. This opens up the possibility to scientists to decode the atomic structure of complex molecules with tiny nanocrystals, presumably completely without crystallisation in the future. These crystals with the size of only billionths or millionths of a metre are much easier to produce than their larger species. In serial femtosecond crystallography, a beam of these tiny crystals is traversed by X-ray laser light and hundreds of thousands scattering images are taken. The series of single X-ray laser images allows to calculate the overall structure.

Chapman, leading scientist at DESY, is the pioneer in the development of this investigation method especially tailored for free-electron lasers. Using the method, he solved the structure of the Cathepsin B enzyme, which is a promising starting point to create a medication against sleeping sickness. The scientific journal Science listed his work among the ten most important discoveries in the year 2012. Chapman's finding of rescuing the scattering image with X-ray lasers before destruction by the intensive light also creates the preconditions to investigate samples almost in their natural environment, thus providing verifiable information about the structure and function of about 100,000 biomolecules which have not yet been decoded.

Recent IUCrJ open access articles from Professor Chapman

  • Expression, purification and crystallization of CTB-MPR, a candidate mucosal vaccine component against HIV-1: Lee et al. (2014). IUCrJ, 1, 305-317; doi:10.1107/S2052252514014900
  • Serial crystallography on in vivo grown microcrystals using synchrotron radiation: Gati et al. (2014). IUCrJ, 1, 87-94; doi:10.1107/S2052252513033939
  • Room-temperature macromolecular serial crystallography using synchrotron radiation: Stellato et al. (2014). IUCrJ, 1, 204-212; doi:10.1107/S2052252514010070

This announcement is reprinted from material at DESY with editorial changes made by IUCr. The source article can be found here.

Posted 11 Dec 2014 

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The times they are a-changin’ – news from Acta Crystallographica Section F

fcover_bigA decade ago Acta Crystallographica Section F was launched with the subtitle Structural Biology and Crystallization Communications under the excellent stewardship of Howard Einspahr and Mitchell Guss. The journal was conceived in response to developments in the field when it was recognized that our community needed a home for the rapid dissemination of structural results and a convenient way to publish crystallization reports. The founding Editors made a commitment to maintain scientific rigor and to best serve our community, the authors and readers. Since 2005 we have all strived to do just that.

For some time now, and driven by advances in our discipline, we have been thinking about what would be considered best for the journal with respect to crystallization papers. We at first decided to change the journal's subtitle to Structural Biology Communications to remove the artificial segregation of crystallization from structural biology and to pave the way for Acta Cryst. F to become a full-fledged structural biology journal. We also analyzed the papers that have focused on crystallization results and decided that in order to streamline their information content, a more formal structure should be put in place for these papers. This led to the development of publBio (http://publbio.iucr.org), which is now widely used to prepare and submit manuscripts for Acta Cryst. F.

We’re not stopping there, we aim to improve the journal still further. We have taken the decision to no longer publish articles on the routine preparation and characterization of macromolecules for which orthologues have already been published or deposited. Furthermore, for a new crystallized macromolecule we expect a degree of characterization not previously required. For example, it will become essential to demonstrate that the correct macromolecule has been crystallized. Further details are available in the new Notes for Authors, available from the Acta Cryst. F author services page.

We are also thinking about requiring the deposition of a diffraction data set together with the submission of a manuscript that reports a successful crystallization. After all, the diffraction data set is evidence for crystallization and is typically described in the paper. We will also ask for further proof of function for enzymes and certain other proteins. The decision to require more data and to publish more interesting macromolecules has been driven by two considerations. Many crystallization communications do not lead to a structural paper or to citations. This suggests that such papers are of little interest or relevance to our community. Increasingly, it is also the case that the structure of the crystallized macromolecule, the subject of the crystallization paper, can be solved and refined quickly. In such a case we would prefer to see the structure published in our journal, with details of the sample preparation and characterization as part of the publication. We believe the outcome of these changes will improve the standard of publications yet maintain support for our community in keeping up to date with the current state of structural biology.

W. N. Hunter and M. S. Weiss
Section Editors, Acta Crystallographica Section F

This is an excerpt from the full editorial which can be found at http://journals.iucr.org/f/issues/2014/12/00/me0557/index.html

Posted 10 Dec 2014 

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Martian crystallography

Water-rich halide hydrate structures have not grabbed the attention of chemists ... until very recently when it was realized that such ionic compounds might create life-bearing aqueous pools temporarily at temperatures as low as 200 K and that such systems might exist on the chilly surface of the planet Mars.

Over the last few years various craft sent to Mars - Viking, Phoenix and Curiosity - have hinted at the chemistry of the Red Planet. Large quantities of salts, including sulfates and chlorides, as well as water droplets have been detected, and geological evidence for aqueous processes includes valleys and slopes that are clearly visible today.

The presence of perchlorate, magnesium and sodium also provides evidence for the possible surface redistribution of water on Mars through hydration/dehydration cycles of such ionic substances and their liquefaction through deliquescence. Of course, Mars has extremes of temperature depending on season from 190 to 283 K, so the presence of liquid water might be a fragile and periodic phenomenon relying entirely on the existence of these cryogenic aqueous salt brines. The physical chemistry of some ionic substances suggests that temporary aqueous solutions might exist at temperatures as low as 200 K. Could such pools, however microscopic, harbour putative microbial life forms?

Chains of hydrated Al atomsWriting in Acta Crystallographica [Schmidt et al. (2014). Acta Cryst. C70, 882-888; doi:10.1107/S2053229614014302], inorganic chemists Horst Schmidt, Erik Hennings and Wolfgang Voigt of TU Bergakademie Freiberg, Germany, have crystallized five interesting hydrates: the nonahydrate of aluminium bromide; the stable pentadecahydrates of aluminium chloride, bromide and iodide; and a metastable heptadecahydrate of the iodide from low-temperature solutions. They have determined the crystal structures of these compounds as part of their ongoing work investigating the crystallization and dissolution close to the lower-temperature extremes observed on Mars.

The three pentadecahydrates of aluminium chloride, bromide and iodide represent the most water-rich hydrates known for aluminium salts, the team says. The team explains that the development of cation hydration spheres in these structures is critical. They found that the pentadecahydrate of the chloride and bromide are isostructural. In the iodide species, half of the Al cations are surprisingly surrounded by two complete hydration spheres, with six water molecules in the primary sphere and twelve in the secondary. And, in the heptadecahydrate of aluminium iodide, this level of hydration was seen with every single Al3+. Indeed, the heptadecahydrate, AlI3.17H2O, is the most water-rich hydrate so far prepared from an aluminium salt, the team reports. However, it crystallizes only as an intermediate phase that changes habit and composition within days to form a pentadecahydrate.

"When freezing-thawing cycles at low temperatures play a role in water redistribution on Mars then one has to expect other enrichments of the elements than on Earth," team member Wolfgang Voigt told us. "The high concentration of perchlorate was the first surprise, others might follow. Further work is directed at developing a general understanding of the crystallization of salt hydrates at low temperatures with halides, perchlorates and sulfates being the focus."
Posted 05 Dec 2014 

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The first X-ray diffraction measurements on Mars

[David Bish]In 2012 the Mars Science Laboratory landed in the fascinating Gale crater. The Gale crater is of such great interest because of the 5.5 km high mountain of layered materials in the middle. This material tells an intricate story of the history of Mars, perhaps spanning much of the existence of this mysterious planet.

Once positioned, the Curiosity rover began field studies on its drive toward Aeolis Mons (also unofficially known as Mount Sharp), the central peak within the crater. Curiosity has travelled more than 9.4 km so far and during its trip up the mountain, Curiosity has begun taking samples of the mountain’s lower slopes.

CheMin is one of ten instruments on or inside Curiosity, all designed to provide detailed information on the rocks, soils and atmosphere. [Bish et al. (2014). IUCrJ, 1, 514-522; doi:10.1107/S2052252514021150] CheMin is actually a miniaturised X-ray diffraction/X-ray fluorescence (XRD/XRF) instrument, approximately the size of a shoebox, that uses transmission geometry with an energy-discriminating CCD detector to obtain unparalleled results in quite challenging conditions.

Five samples have been analysed by CheMin so far, namely a soil sample, three samples drilled from mudstones and a sample drilled from a sandstone. Rietveld and full-pattern analysis of the XRD data have revealed a complex mineralogy, with contributions from parent igneous rocks, amorphous components and several minerals relating to aqueous alteration, for example clay minerals and hydrated sulphates. In addition to quantitative mineralogy, Rietveld refinements also provide unit-cell parameters for the major phases, which can be used to infer the chemical compositions of individual minerals and, by difference, the composition of the amorphous component. Coincidentally CheMin’s first XRD analysis on Mars coincided with the 100th anniversary of the discovery of XRD by von Laue.

So far CheMin has returned excellent diffraction data comparable in many respects with data available on[powder diffraction pattern from Martian soil] Earth. It has managed this even though several aspects of the instrument, particularly its small size limit the quality of the XRD data. These limitations could, however, be improved through modification of the instrument geometry. One of the most significant issues limiting remote operation is the requirement for powder XRD of a finely powdered sample. CheMin largely surmounts this difficulty through the use of its unique sample vibration device.

Data obtained so far has already provided new insights into processes on Mars, and the instrument promises to return data that will answer numerous questions and shed further light on the history of the Gale crater.

Work is already progressing in developing an upgraded instrument with changes in the reflection geometry. Coupled with data-processing software interface advances, we may see future improvements to non-contact diffraction analysis of the surfaces of planetary bodies.

A video of Professor David L. Bish presenting work from the Mars science mission can be viewed here. The lecture was part of a series of talks organised by the University of Liverpool as part of their Science & Society Lecture Series.

Posted 27 Nov 2014