International Union of Crystallography Commission on Crystallographic Apparatus single-crystal radiation damage survey

The integrated intensities of up to 21 different reflections were measured, as a function of increasing X-radiation exposure, from single crystals of each of nine materials of widely different chemical composition. Eight investigators from three countries took part in the Survey. The materials reported included an inorganic mixed oxide, three aromatic molecules, four metal-organic complexes, and an antibiotic. Changes in intensity were detected in each case, some large, others of marginal significance. In no case did all reflections studied change uniformly: in one crystal, some reflections decreased by as much as an order of magnitude after radiation exposure. In five crystals, some reflections increased as others decreased in intensity. Recommendations are made for including a diagnostic check of possible radiation damage produced in the course of measuring integrated intensities for crystal-structure determinations.