Premium
Fast synthesis and refinement of the atomic pair distribution function
Author(s) -
Coelho A. A.,
Chater P. A.,
Kern A.
Publication year - 2015
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s1600576715007487
Subject(s) - gaussian , function (biology) , pair distribution function , algorithm , context (archaeology) , distribution (mathematics) , atomic number , gaussian function , computer science , distribution function , rietveld refinement , gaussian elimination , statistical physics , physics , computational physics , mathematics , atomic physics , optics , mathematical analysis , diffraction , quantum mechanics , paleontology , evolutionary biology , biology
A fast method for calculating the atomic pair distribution function is described in the context of performing refinements of structural models. Central to the speed of synthesis is the approximation of Gaussian functions of varying full widths at half‐maximum using a narrower Gaussian with a fixed full width at half‐maximum. The initial Gaussians are first laid down as delta functions which are then convoluted with the narrower Gaussian to form the final pattern. The net result is an algorithm, which has been included in the Rietveld refinement computer program TOPAS , that synthesizes and refines structural parameters a factor of 300–1000 times faster than alternative algorithms/programs, with speed advantages increasing as the number of atomic pairs increases.