Journal of Applied Crystallography

Volume 42, Part 3 (June 2009)

research papers

J. Appl. Cryst. (2009). 42, 385-391 [ doi:10.1107/S0021889809008450 ]

Implementation and use of robust refinement in powder diffraction in the presence of impurities

K. H. Stone, S. H. Lapidus and P. W. Stephens

Abstract: A modification to the usual least-squares analysis is implemented for the robust refinement of structural parameters from powder diffraction data in the presence of unmodeled impurities. This is accomplished in the program TOPAS-Academic by an iterative reweighting of the data as the model is refined. The method is tested and characterized using mixtures of known materials, acetaminophen and ibuprofen. The technique is also used to refine two previously unknown structures.

Keywords: least-squares analysis; Rietveld refinement; robust refinement; powder diffraction data; unmodeled impurities.


	Rietveld powder data file (CIF format) (203.7 kbytes) [ doi:10.1107/S0021889809008450/db5058sup2.rtv ] Contains datablock profile1

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup3.rtv ] Contains datablock profile2

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup4.rtv ] Contains datablock profile3

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup5.rtv ] Contains datablock profile4

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup6.rtv ] Contains datablock profile5

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup7.rtv ] Contains datablock profile6

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup8.rtv ] Contains datablock profile7

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup9.rtv ] Contains datablock profile8

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup10.rtv ] Contains datablock profile9

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup11.rtv ] Contains datablock profile10

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup12.rtv ] Contains datablock profile11

	Rietveld powder data file (CIF format) (152.9 kbytes) [ doi:10.1107/S0021889809008450/db5058sup13.rtv ] Contains datablock profile12

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