International
Tables for
Crystallography
Volume C
Mathematical, physical and chemical tables
Edited by E. Prince

International Tables for Crystallography (2006). Vol. C, ch. 8.6, p. 711

Section 8.6.2.1. Indexing

A. Albinatia and B. T. M. Willisb

aIstituto Chimica Farmaceutica, Università di Milano, Viale Abruzzi 42, Milano 20131, Italy, and bChemical Crystallography Laboratory, University of Oxford, 9 Parks Road, Oxford OX1 3PD, England

8.6.2.1. Indexing

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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]): `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[link]), Pawley (1981[link]), Cheetham (1993[link]) and Werner (2002[link]).

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.
Pawley, G. S. (1981). Unit-cell refinement from powder diffraction scans. J. Appl Cryst. 14, 357–361.
Shirley, R. (1980). Data accuracy for powder indexing. Natl Bur. Stand (US) Spec. Publ. No. 567, pp. 361–382.
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.








































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