Refinement of modulated structures against X-ray powder diffraction data with JANA2000

Titelangaben

Dusek, Michal ; Wunschel, Markus ; Dinnebier, Robert E. ; van Smaalen, Sander:
Refinement of modulated structures against X-ray powder diffraction data with JANA2000.
In: Journal of Applied Crystallography. Bd. 34 (2001) Heft 3 . - S. 398-404.
ISSN 1600-5767
DOI: https://doi.org/10.1107/S0021889801003302

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Abstract

JANA is a computer program for the refinement and analysis of periodic and aperiodic (incommensurately modulated structures and composite crystals) crystal structures. Here a new module is introduced that allows Rietveld refinements against powder diffraction data. It is shown that JANA2000 provides a state-of-the-art description of the peak profiles. A re-analysis of the low-temperature structure of (CO)xC60 showed that the application of icosahedral symmetry restrictions to the C60 molecule leads to a better description of the electron density and to a corrected position of the CO molecule as compared with a rigid-body refinement. The incommensurately modulated structure of NbTe4 has been successfully refined against X-ray powder diffraction data. The structural parameters are equal to, but less accurate, than the parameters obtained from a single-crystal study.