The key shift method. II. Application to superstructures of molecular crystals

Abstract

The key shift method, a kind of minimum residual method, has been successfully applied to the structure analysis of superstructures, one known and one unknown, of molecular crystals with eight and eleven non-hydrogen atoms respectively in the asymmetric units. In the latter case, symmetry considerations of the substructure-superstructure relationship were important for the solution. In another case of a known superstructure in which there were 30 independent non-hydrogen atoms at the start of the analysis, shifts of rigid-body molecules were found to be more efficient than those of individual atoms.