A new vision for Acta Crystallographica Section A

The impact of crystallography is profound. A detailed knowledge of material structure is a prerequisite to any understanding of material properties, and materials are at the heart of just about every next-generation technology. For example, advanced complex materials hold the key to many solutions to our biggest problems in sustainable energy, health and the environment. Acta Crys-tallographica Section A (Acta A) is the foundation on which the whole suite of IUCr crystallography journals are built, containing as it does papers describing fundamental developments in crystallographic theory and practice. It reports developments in the method rather than the results of applying those methods and, as such, holds a special place in the firmament of the IUCr journals. The papers in Acta A are reasonably well cited (impact factor 2.24) but the impact of the work they describe has much farther reach, forming the basis of transfor-mative discoveries reported in journals from Nature and Science all the way to specialized journals from chemistry and physics to planetary science and pharmaceuticals , with the other IUCr journals in between. One hundred years on from the first experiments in X-ray crystallography, and as we approach the International Year of Crystallography in 2014, it is timely to revisit the state of crystallography and advances taking place in studies of material structure. The landscape in this regard looks very different from the way it did even ten years ago, and unrecognizable from 30 years ago, when synchrotron X-ray sources first came onto the scene, from the methods being used to probe the structure, to the computing resources that are now available, to the very nature of the materials-structure questions being studied. One of the greatest challenges is the study of nanostructures: far from the crystallographic ideal of an infinite periodically repeating lattice, but of fundamental importance in applications such as battery electrodes, catalytic stacks and cosmetics. Is this crystal-lography? One would have to say yes. Material properties depend sensitively on defects, but many functional materials, fast-ion conductors being a case in point, have so many defects that it is hard to distinguish what is defect and what is structure; the defects are intrinsic and not a materials-processing-dependent microstructural issue more at home in Acta Materiala. On the sources side, X-ray free-electron lasers (X-FELs) are currently under rapid development worldwide; they produce intense X-ray pulses with a peak brilliance a billion times higher than synchrotron radiation and …