title: Recent developments in classical density modification.
abstract: Classical density-modification techniques (as opposed to statistical approaches) offer a computationally cheap method for improving phase estimates in order to provide a good electron-density map for model building. The rise of statistical methods has lead to a shift in focus away from the classical approaches; as a result, some recent developments have not made their way into classical density-modification software. This paper describes the application of some recent techniques, including most importantly the use of prior phase information in the likelihood estimation of phase errors within a classical density-modification framework. The resulting software gives significantly better results than comparable classical methods, while remaining nearly two orders of magnitude faster than statistical methods.
authors.affiliation: Department of Chemistry, University of York, Heslington, York YO10 5DD, England. cowtan@ysbl.york.ac.uk
authors.forename: Kevin
authors.initials: K
authors.lastname: Cowtan
mesh_terms: D016880:Anisotropy; D003198:Computer Simulation; D018360:Crystallography, X-Ray / Q000379:methods*; D012985:Software Design
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