Fortran IV least squares computer program for the profile refinement of cubic powder diffraction patterns with cubic harmonic functions.
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Date
1980-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Australian Atomic Energy Commission
Abstract
A cubic harmonic least squares Fortran IV program has been written for the refinement of cubic structures with disordered or rotating groups, e.g. MX6, which cannot be refined satisfactorily with classical methods. The program has been used to refine neutron powder data for the plastic cubic phases of MoF6, WF6, SF6 and Na2UBr6. The anion density is assumed to lie on the surface of a sphere of radius the M-X distance. The powder pattern intensities and relevant crystal data are input and the program refines the M-X distance, a scale factor, an overall Debye-Waller factor and the cubic harmonic coefficients by a full matrix, least squares treatment. The program is adaptable, with small changes in the structure factor expression, to other disordered cubic structures.
Description
Keywords
Fortran, Computer codes, Crystals, Neutron diffraction
Citation
Taylor. J. C. (1980). Fortran IV least squares computer program for the profile refinement of cubic powder diffraction patterns with cubic harmonic functions (AAEC/E488). Lucas Heights, NSW: Australian Atomic Energy Commission.