Durward W. J. Cruickshank. 7 March 1924—13 July 2007

Abstract

Durward Cruickshank was an eminent crystallographer and structural chemist, whose mathematical abilities transformed the precision of the molecular structures determined in three dimensions by X-ray crystal structure analysis. This technique is very widely applied to determine the three-dimensional (3D) shapes of molecules of importance in biology, chemistry, mineralogy, materials science and physics. Durward's first publication was on this topic, with Sir Gordon Cox. It represents a lifelong interest of Durward in the precision of crystal structure analysis and extended also to gas-phase electron diffraction. His research publications spanned an amazing 60 years and he had a direct influence on over 900 000 chemical crystal structures, the number currently determined and held in the Cambridge Structure Database alone. Proteins took his attention for research in his last decade, and his diffraction precision index (DPI) indicator of the precision of a protein structure is added regularly to entries in the Protein Data Bank. In his ‘retirement’ he contributed, with one of the authors of this memoir, J.R.H., and various colleagues in the UK and the USA, to the development of the ‘Laue diffraction’ white beam synchrotron method, applied today to sub-nanosecond X-ray crystallography measurement techniques, and also to study micron sized, i.e. tiny, crystal samples. The method has also led ultimately to more effective exploitation of neutron beams from research reactors for crystallographic studies of the hydrogenation details of molecules.