Direct space and simultaneous direct-reciprocal space optimization models for phasing structures
Year: 2008
Type: article
Abstract: The phase problem has recently been approached via combinatorial optimization techniques and the resulting Sieve method has been demonstrated to be effective for phasing centrosymmetric structures [1].The purpose of the current work is to develop a more robust model for accurate phasing in the presence of odd triplets, and more important, to provide a combinatorial optimization approach to phasing non-centrosymmetric crystals.Two mixed-integer linear programming models for phasing are proposed; both of which include the introduction of specific direct space constraints with one additionally operating in reciprocal space.Direct space is constrained through sampling of electron density on a grid.Structure factors are calculated at these points in terms of the integer variables, which describe the phases.Bounds are then formulated using experimental data.Computational results are presented for a variety of structures.References [1]
Authors: A.B. Smith, N.V. Sahinidis
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2317917808