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Updated: Jul 14, 2026

X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects
Published on: June 8, 2016
Enhanced efficiency of direct-space structure solution from powder X-ray diffraction data in the case of
Andrew J Hanson1, Eugene Y Cheung, Kenneth D M Harris
1School of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT Wales, UK.
Abstract:
A strategy is reported for assessing the feasibility of molecular conformations within direct-space structure-solution calculations of organic molecular crystal structures from powder X-ray diffraction data, focusing in particular on the genetic algorithm technique for structure solution in which fitness is defined as a function of the whole-profile figure-of-merit Rwp. The strategy employs a readily computed distance-based function to assess the feasibility of the molecular conformation in each trial structure generated in the genetic algorithm calculation, and structures considered to have low-feasibility conformations are penalized within the evolutionary process. The strategy is shown to lead to significant improvements in the success rate of structure-solution calculations in the case of flexible molecules with a significant number of conformational degrees of freedom.
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