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International
Tables for Crystallography Volume C Mathematical, physical and chemical tables Edited by E. Prince © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. C. ch. 8.6, p. 711
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The first step in refinement is the indexing of the pattern. As the Rietveld method is often applied to the refinement of data for which the unit-cell parameters and space group are already known, there is then little difficulty in indexing the pattern, provided that there are a few well resolved lines. Without this knowledge, the indexing requires, as a starting point, the measurement of the d values of low-angle diffraction lines to high accuracy. According to Shirley (1980![[link]](/graphics/greenarr.gif)
): `Powder indexing works beautifully on good data, but with poor data it usually will not work at all'. The indexing of powder patterns and associated problems are discussed by Shirley (1980), Pawley (1981), Cheetham (1993) and Werner (2002).
References
Cheetham, A. K. (1993). Ab initio structure solution with powder diffraction data. The Rietveld method. IUCr Monographs on Crystallography, No. 5, edited by R. A. Young, pp. 276–292. Oxford University Press.Google Scholar
Pawley, G. S. (1981). Unit-cell refinement from powder diffraction scans. J. Appl Cryst. 14, 357–361.Google Scholar
Shirley, R. (1980). Data accuracy for powder indexing. Natl Bur. Stand (US) Spec. Publ. No. 567, pp. 361–382.Google Scholar
Werner, P. E. (2002). Autoindexing. Structure determination from powder diffraction data. IUCr Monographs on Crystallography, No. 13, edited by W. I. F. David, K. Shankland, L. B. McCusker & Ch. Baerlocher, pp. 118–135. Oxford University Press.Google Scholar
