|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.|
It is with great sadness that we announce the death of Frank Allen on 10 November 2014, aged 70.
Frank joined the Chemical Crystallography Group at the University of Cambridge in 1970 and played a pivotal role in the establishment of the Cambridge Structural Database. He went on to become the Scientific Director and then the Executive Director of the Cambridge Crystallographic Data Centre.
Following his retirement in 2008, Frank remained with the CCDC as an Emeritus Research Fellow, enabling him to continue to indulge his passion for structural chemistry.
Frank’s research involved collaboration with many scientists around the world, resulting in over 200 papers. He was also a wonderful teacher, supervising more than 20 doctoral students and introducing many more to structural chemistry through workshops over many years.
His contributions to other influential organisations, his vigorous editorship of Acta Crystallographica, the numerous conferences he organised and presentations he made meant Frank was known to and respected by crystallographers the world over.
Frank has long been a leading figure in international crystallography, and was a wonderful colleague, becoming a friend to all those who worked with him. He will be sadly missed.
A group of crystallographers came together on Wednesday 19 November at the RSC Chemistry Centre, Burlington House, London, UK to discuss Communicating Crystallography as part of the Chemical Crystallography Group Autumn Meeting 2014. The morning session opened with energetic presentations focusing on outreach from Anna Warren (Diamond Light Source), Peter Hoare (University of Newcastle) and Chick Wilson (University of Bath). The afternoon session, which looked at the publishing process and some of the latest activities from the Royal Society of Chemistry, started with Guy Jones, followed by Serin Dabb and then David Sait. After tea, the final session began with a presentation from Brian McMahon (IUCr) entitled “From structural data to structural knowledge”. A discussion of data, databases and deposition with a panel comprising John Helliwell (University of Manchester), Serin Dabb (RSC) and Ian Bruno (CCDC) brought the event to a close. A link to the individual presentations or information relating to them will be made available shortly.
From crystals of cancer drugs to atomic patterns drawn in the sand, a new photography exhibition at the Royal Albert Hall, London, UK perfectly captures the beauty and intricacy inherent in the science of crystallography.Illuminating Atoms, by the photographer Max Alexander, depicts a series of documentary images of crystallography experiments in action alongside portraits of modern-day crystallographers. The exhibition, which is sponsored by the Science & Technology Facilities Council (STFC), the Wellcome Trust, GSK, AstraZeneca, Pharmorphix and the Diamond Light Source, conveys the untold story of crystallography, demonstrating the range of science taking place and the rich and vibrant community working in this field. The final opportunity to view Illuminating Atoms will be Saturday 29 November from 10am to 4pm; for more information, please visit www.stfc.ac.uk/illuminating_atoms_portraits.
Further activities promoting crystallography take place this week. The article "IYCr2014: Spreading the Word About Crystallography in an International Year" by Brian McMahon and Michele Zema (IUCr) will be discussed online from 24 to 26 November during the 2014 Fall Newsletter virtual conference of the DivCHED CCCE of the American Chemical Society. The full article is available here. To take part in the online discussion you need to set up a free account at http://confchem.ccce.divched.org/2014FallCCCENL.
Finally, if you are attending the MRS Fall Meeting in Boston, USA next week, do take the time to visit the IUCr booth #114 where we’ll be pleased to see you. At our booth you can
· learn more about our journal portfolio including our new gold open-access journal, IUCrJ, and other titles in our portfolio
· find out details of our “meet the editor” session taking place during the afternoon coffee break on Wednesday 3 December with Dr Andrew Allen, Editor, Journal of Applied Crystallography
· ask our Business Development Manager about open-access options and how Altmetrics and Kudos can help you promote your own work
· enter our prize draw to win a copy of A Little Dictionary of Crystallography.We look forward to seeing you there.
X-rays have been at the heart of imaging since their discovery at the end of the nineteenth century. Now, Pierre Thibault and colleagues at University College London, UK and the Paul Scherrer Institute in Switzerland, hope that a new twist on an old favorite will extend and give them dose-limited resolution and sensitivity through the development of X-ray ptychography.
X-ray ptychography is a scanning coherent diffractive imaging technique, the team explains. The technique first suggested in the 1970s involves illuminating the sample with a structured, often confined source and measuring the resulting diffraction pattern for different overlapping positions of the sample, the term is from the Greek "fold" and "writing". Ultimately, ptychography promises to solve the diffraction-pattern phase problem in X-ray studies.
Coherent diffractive imaging (CDI) techniques, of which ptychography is just one, are all underpinned by the lack of a lens to focus the image. Instead of focusing, a mathematical algorithm is used to reconstruct the image of the sample from the collected diffraction patterns. Such a lensless system thus bypasses many of the technical constraints of lenses, which for X-rays are often inefficient, may introduce aberrations, and strongly limit resolution. Lensless, however, means phase is lost, which is where the overlapping folds of ptychography are exploited.
"Ptychography may approach imaging speeds familiar from full-field methods while retaining its inherently quantitative nature and metrological versatility," the team explains Thibault et al. (2014). J. Synchrotron Rad. 21,1011-1018; doi:10.1107/S1600577514015343. "Beyond promises of high throughput, spectroscopic applications in three dimensions become feasible, as do measurements of sample dynamics through time-resolved imaging or careful characterization of decoherence effects." The team suggests that additional technological and analytical advances in bright X-ray sources are now needed to help this field mature and to allow it to enter the realm of high-throughput studies and even three-dimensional spectroscopy.
"Ptychography's active development and sustained rate of successes hints at its potential as an important player in contemporary questions on data acquisition strategies, information content and feature extractions," the team reports, hinting that so-called "big data" methods of the kind usually reserved for particle physics and high-speed tomography, will come to the fore.
"In a way there are many next steps," Thibault told the IUCr. "In the paper we mention 'quantitative improvements', namely improve speed and size of field of view, and 'qualitative improvements', or improving resolution and sensitivity. Beyond this, the goal would be moving to four dimensions, that is adding one extra axis, either spectrum (spectro-tomography) or time (tomographic movies).
The Thibault paper forms part of the special issue in the Journal of Synchrotron Radiation: Diffraction-Limited Storage Rings and New Science Opportunities. Guest Editors: Mikael Eriksson and J. Friso van der Veen.
|Figure 1: 2014 Nobel Prize winners for Physics|
Epitaxial layers of gallium nitride (GaN) – material that exists in the laboratory only – on single-crystal sapphire substrate produce a blue light which can be converted to white light using a phosphor coating. Today these new LEDs are replacing traditional light bulbs and fluorescent tubes worldwide. The white LED lamps are bright, efficient and long lasting. They have improved the quality of life of billions of people around the world: owing to low power requirements these lamps can be powered by cheap, local, solar energy. This discovery directly benefits all of us.
A great deal of information about the Nobel Prize Winners, the blue light emitting diode and its advantages for the whole world can be found in the scientific literature and on the internet. There are interviews, press releases and popular articles.
The reason why we are writing this note is to stress how important to this world-changing discovery is the challenging crystal growth and epitaxial deposition work performed at the beginning of the success path.
To achieve the next step, leading to a high efficiency laser, a new, reliable method of obtaining bulk single crystals of GaN had to be created, implemented and become affordable. This is happening right now as large, high quality GaN crystals are being grown by either high-pressure or amonothermal methods. As this is achieved, many other obstacles, from cutting the bulk crystal in a specific orientation to reducing the number of dislocations, still have to be overcome.
|Figure 2: Gallium nitride crystal. Courtesy of the archives of the IWC Sciences|
|Figure 3: Final of the Spanish schools crystallisation competition|
For many years the IUCr has regularly and generously supported crystal-growth schools and conferences around the world an example can be seen here. These meetings act as forums where new ideas can be formed, discussed and promoted. In the time of scientific budget cuts and limits on basic research in many countries these IUCr activities, as well as those such as the international crystal growth competition for elementary and high-school students, create new interest in the old art of growing crystals. These activities build solid scientific foundations within the future generation of researchers, who – now in their school years – cannot only enjoy the happiness of creating something new and very material: the crystal, but also – and this is extremely important at any age – be applauded and recognized for doing it.Hanna Dabkowska and Andrea Zappettini
The United Nations proclaimed 2014 the International Year of Crystallography. Due to many of the activities and events taking place throughout the year, it is obvious, more so than in previous years, how crystallography strengthens and enriches all natural sciences. Take for example the breathtaking developments at modern large scale facilities, like third generation synchrotrons, X-ray free-electron lasers and neutron spallation sources, and the various remarkable improvements recently made to home facilities. The sealed X-ray tube has been almost totally replaced today by reliable microfocus or rotating anode sources, stronger by many orders of magnitude when compared to W. C. Röntgen's original device. The same is valid for detector technology, where the original film or scintillation detector, even the image plate, is nowadays almost totally substituted by charge-coupled devices (CCDs, CMOSs). Even they will become outdated very soon when we look at the most recent developments of the single-photon counting hybrid pixel area detector.
This new class of detector combines the virtues of speed of an area detector with the advantageous low noise and extremely high dynamic range of a point detector. The first pixel detectors have been designed and optimized for use with synchrotrons (e.g. PILATUS or EIGER from Dectris, or XPAD from imXPAD). Unfortunately, due partly to cost, data collection and software integration issues, these detectors have not yet reached the typical university laboratory. That is until now [Wenger et al. (2014). Acta Cryst. B70, 783-791; doi: 10.1107/S2052520614017338]. For the first time a group of authors present a pixel detector mounted on a commercial goniometer, equipped with a microfocus X-ray source, to generate high-resolution X-ray data.
The researchers have shown in the paper that high quality diffraction data suitable for accurate charge density studies can be collected by following their set-up.
The charge-density community will be eager to see further developments from this team such as a reduction in data acquisition time, addressing blind detector areas and improved data reduction to tackle estimated systematic errors and intensity variances.
This news story is a short excerpt taken from the commentary [Stalke (2014). Acta Cryst. B70, 781-782; doi: 10.1107/S2052520614021349].
The relaunch of Acta Crystallographica Section E (http://journals.iucr.org/e) in June this year (2014) saw the publication of the first papers in the new Research Communication format designed to bring out the science behind the structure determination.
Reports are no longer limited to a short description of a single structure and figures are no longer relegated to the Supporting information. We are delighted to see that an increasing number of authors are choosing to publish their work as a Research Communication, with the numbers of these articles increasing every month. The November issue includes the one hundredth paper to be published in this format, so what better time to celebrate the great breadth in the range and scope of the Research Communications published so far?
Authors are positively encouraged to report and discuss related structures in a single Research Communication rather than publishing a series of short structural reports. We are pleased to see that papers reporting two structures are a now regular feature and one three-structure paper has been published. Authors have made the most of the opportunity to include extra tables and figures in the published paper to illustrate their results and enhance the discussion of the underlying science.
We would like to see even more of our authors old and new submit to the journal in this format. Our editors and many of our authors already take advantage of the IUCr's publCIF software to write and edit their papers using a word-processing environment. publCIF takes a crystallographic information file (CIF) and prepares a formatted paper (preprint) in the Research Communication style. The CIF and the preprint are presented side-by-side and can both be edited - changes made to one are applied to the other as you type. publCIF also includes many useful editorial tools to help you write your paper. It can be used to add data items required for publication, prepare standard and customized geometry tables, check your CIF for both syntax and completeness, print or export a preprint of your paper, check the references and more. Using publCIF, a Research Communication can be produced with just a little extra effort. Be sure to use the latest version of publCIF, which is available to download free of charge from http://publcif.iucr.org .
A large part of the success of the new Research Communication format is down to our dedicated team of Co-editors who are doing an excellent job in advising authors how to promote their science. On behalf of the Section Editors of Acta E, I would like to take this opportunity to thank them for helping make Acta Crystallographica Section E the obvious choice for disseminating the results of the excellent crystallography that is being carried out by our authors worldwide.
This announcement is a short excerpt taken from the editorial [Stoeckli-Evans (2014). Acta Cryst. E70, 454-455; doi:10.1107/S1600536814023393].
See our earlier news story covering Acta Crystallographica Section E editorial changes here.