CRYSTALS version 12: software for guided crystal structure analysis Betteridge, Paul W. Carruthers, J. Robert Cooper, Richard I. Prout, K. Watkin, David J. Chemical crystallography Crystallography refinement and analysis single crystal small molecule X-ray diffraction crystal structure The determination of small-molecule structures from single-crystal X-ray data is being carried out by researchers with little or no crys- tallographic training. At the same time, completely automatic crystal structure analysis can still only be achieved under very favourable conditions. Many of the problems that cause automatic systems to fail could be resolved with suitable chemical insight, and until this is built- in, programs continue to need human guidance. CRYSTALS version 12 contains a modern crystallographic human-interface design, and novel strategies incorporating chemical knowledge and sensible crystallographic guidance into crystal structure analysis software. 2003-December text Article: post-print Published Peer reviewed Publisher's version Published born digital doi: 10.1107/S0021889803021800 issn: 0021-8898 Oxford Research Archive internal ID: ora:6555 http://journals.iucr.org/j ora:6555 en http://journals.iucr.org/j 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:20bf3713-d879-46e2-bd40-a27cc9539e54