CRYSTALS enhancements: Refinement of atoms continuously disordered along a line, on a ring or on the surface of a sphere

Abstract

The program CRYSTALS [Betteridge, Carruthers, Cooper, Prout & Watkin (2003). J. Appl. Cryst. 36, 1487] has been extended to include an option for the refinement of a continuous electron density distribution lying along a line, a ring or on the surface of a sphere. These additional non-atomic electron distributions can be refined in any combination with traditional anisotropically distributed spherical atoms, including the refinement of 'partial' atoms overlapping with the special electron distributions.