CRYSTALS enhancements: refinement of atoms continuously disordered along a line, on a ring or on the surface of a sphere Schroeder, Ludger Watkin, David J. Cousson, Alain Cooper, Richard I. Paulus, Werner Crystallography 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. 2004 text Article: post-print Published Peer reviewed Published born digital doi: 10.1107/S0021889804009847 issn: 0021-8898 Oxford Research Archive internal ID: ora:6553 http://journals.iucr.org/j/issues/2004/04/00/os5010/ ora:6553 en http://journals.iucr.org/j/issues/2004/04/00/os5010/ Readers of this article may, without needing to seek permission from the IUCr: 1) save to hard disk a local copy of the article for their personal use; 2) print off one or more copies of the article for their personal use (they may not disseminate copies to third parties; 3) include brief extracts from the article or abstract, without revision or modification, in their own publications so long as the original source is acknowledged and a full bibiographic reference given. For all other uses, please see the page "Permissions requests" (http://journals.iucr.org/services/permissions.html). urn:uuid:d46ca9b2-db4a-4c18-98e1-1b49a4443991