NXFit: a program for simultaneously fitting X‐ray and neutron diffraction pair‐distribution functions to provide optimized structural parameters. (1st October 2014)

• Record Type: Journal Article
• Authors: Pickup, David; Moss, Robert; Newport, Robert
• Is Part Of: Journal of applied crystallography. Volume 47:Part 5(2014:Oct.)
• Page Start: 1790
• Page End: 1796
• Publication Date: 2014-10-01
• Subjects: Crystallography -- Periodicals; 548.05
• DOI: 10.1107/S160057671401824X
• Languages: English
• ISSNs: 0021-8898

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p> <italic>NXFit</italic> is a program for obtaining optimized structural parameters from amorphous materials by simultaneously fitting X‐ray and neutron pair‐distribution functions. Partial correlation functions are generated in <italic>Q</italic> space, summed and Fourier transformed for comparison with the experimental data in <italic>r</italic> space. <italic>NXFit</italic> uses the Nelder–Mead method to vary a set of `best guess' parameters to achieve a fit to experimentally derived data. The output parameters from <italic>NXFit</italic> are coordination number, atomic separation and disorder parameter for each atomic correlation used in the fitting process. The use of <italic>NXFit</italic> has been demonstrated by fitting both X‐ray and neutron diffraction data from two quite different amorphous materials: a melt‐quenched (Na₂O)_0.5(P₂O₅)_0.5 glass and a (TiO₂)_0.18(SiO₂)_0.82 sol–gel.</p> </abstract>