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A novel powder diagrams indexing, using classical geometry

Published online by Cambridge University Press:  30 November 2012

M.L. Ettorche*
Affiliation:
Laboratoire de Cristallographie, Département de Physique, Faculté des Sciences, Université Mentouri Constantine, Route Ain El Bey, Constantine 25000, Algeria
M. Sebais
Affiliation:
Laboratoire de Cristallographie, Département de Physique, Faculté des Sciences, Université Mentouri Constantine, Route Ain El Bey, Constantine 25000, Algeria
Z. Hammoudi
Affiliation:
Laboratoire Signaux et Systèmes de Communication, Département d'Electronique, Faculté de Sciences de l'ingénieur, Université Mentouri Constantine, Route Ain El Bey, Constantine 25000, Algeria
*
a)Author to whom correspondence should be addressed. Electronic mail: [email protected]

Abstract

Based only on a geometrical approach, we present a technique to index powder diffraction diagrams. This would allow us to find the cell parameters from the experimental data. It is well known that methods proposed in the literature make a direct use of the experimental data to build the cell, whereas our approach exploits them to calculate theoretical values, which could be multiples of two of the three vectors' lengths of the unit cell, and then uses them along with the experimental values. To show the effectiveness of the proposed algorithm, several examples, requiring only minor limitations in linear dimensions (<35 Å) and volume (<4500 Å3), are treated. For all considered cases, except the triclinic symmetry that is time consuming, the corresponding FORTRAN routine is executed in a reasonable time (<3 min with a 3 GHz processor).

Type
Technical Articles
Copyright
Copyright © International Centre for Diffraction Data 2012

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References

Altomare, A., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Rizzi, R., and Werner, P.-E. (2000). “New techniques for indexing: N-TREOR in EXPO,” J. Appl. Crystallogr. 33, 11801186.CrossRefGoogle Scholar
Altomare, A., Campi, G., Cuocci, C., Eriksson, L., Giacovazzo, C., Moliterni, A., Rizzi, R., and Werner, P.-E. (2009). “Advances in powder diffraction pattern indexing: N-TREOR09,” J. Appl. Crystallogr. 42, 768775.CrossRefGoogle Scholar
Bergmann, J., Le Bail, A., Shirley, R., and Zlokazov, V. (2004). “Renewed interest in powder diffraction data indexing,” Z. Kristallogr. 219, 783790.CrossRefGoogle Scholar
Boultif, A. and Louër, D. (1991). “Indexing of powder diffraction patterns for low-symmetry lattices by the successive dichotomy method,” J. Appl. Crystallogr. 24, 987993.CrossRefGoogle Scholar
Boultif, A. and Louër, D. (2004). “Powder Pattern Indexing with the dichotomy method,” J. Appl. Crystallogr. 37, 724731.CrossRefGoogle Scholar
De Wolff, P. M. (1968). “A simplified criterion for the reliability of a powder pattern Indexing,” J. Appl. Crystallogr. 1, 108113.CrossRefGoogle Scholar
Dong, C., Wu, F., and Chen, H. (1999). “Correction of zero shift in powder diffraction patterns using the reflection-pair method,” J. Appl. Crystallogr. 32, 850853.CrossRefGoogle Scholar
Kariuki, B. M., Belmonte, S. A., McMahon, M. I., Johnston, R. L., Harris, K. D. M., and Nelmes, R. J. (1999). “A new approach for indexing powder diffraction data based on whole-profile fitting and global optimization using a genetic algorithm,” J. Synchrotron Radiat. 6, 8792.CrossRefGoogle Scholar
Le Bail, A. (2004). “Monte Carlo indexing with McMaille,” Powder Diffr. 19,, 249254.CrossRefGoogle Scholar
Le Bail, A., Duroy, H., and Fourquet, J. L. (1988). “Ab-initio structure determination of LiSbWO6 by X-ray powder diffraction,” Mater. Res. Bull. 23, 447452.CrossRefGoogle Scholar
Louër, D. and Vargas, R. (1982). “Indexation automatique des diagrammes de poudre par dichotomies successives,” J. Appl. Crystallogr. 15, 542545.CrossRefGoogle Scholar
Louër, D. and Boultif, A. (2006). “Indexing with the successive dichotomy method, DICVOL04,” Z. Kristallogr. Suppl. 23, 225230.CrossRefGoogle Scholar
Louër, D. and Boultif, A. (2007). “Powder pattern indexing and the dichotomy algorithm,” Z. Kristallogr. Suppl. 26, 191196.CrossRefGoogle Scholar
Neumann, M. A. (2003). “X-Cell: a novel indexing algorithm for routine tasks and difficult cases,” J. Appl. Crystallogr. 36, 356365.CrossRefGoogle Scholar
Smith, G. S. and Snyder, R. L. (1979). “F N: A criterion for rating powder diffraction patterns and evaluating the reliability of powder-pattern indexing,” J. Appl. Crystallogr. 12, 6065.CrossRefGoogle Scholar
Visser, J. W. (1969). “A fully automatic program for finding the unit cell from powder data,” J. Appl. Crystallogr. 2, 8995.CrossRefGoogle Scholar
Werner, P.-E., Eriksson, L., and Westdahl, M. (1985). “TREOR, a semi-exhaustive trial-and-error powder indexing program for all symmetries,” J. Appl. Crystallogr. 18, 367370.CrossRefGoogle Scholar