Contemporary Advances in the Use of Powder X-Ray Diffraction for Structure Determination.

Many crystalline solids cannot be prepared in the form of single crystals of sufficient size and/or quality for investigation using single-crystal X-ray diffraction techniques, and the opportunity to carry out structure determination using powder diffraction data is therefore essential to understand the structural properties of such materials. Although the refinement stage of the structure determination process can be carried out fairly routinely from powder diffraction data using the Rietveld profile refinement technique, solving crystal structures directly from powder data is associated with several intrinsic difficulties. Nevertheless, substantial progress has been made in recent years in the scope and potential of techniques in this field. This article aims to highlight the types of structural problems for which structure determination may now be tackled directly from powder diffraction data, and contemporary applications across several chemical disciplines are presented. A brief survey of the underlying methodologies is given, with some emphasis on recently developed techniques for carrying out the structure-solution stage of the structure-determination process.