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Rigid body refinements in GSAS/EXPGUI

Published online by Cambridge University Press:  06 March 2012

Charles H. Lake*
Affiliation:
Indiana University of Pennsylvania, Indiana, Pennsylvania 15705
Brian H. Toby*
Affiliation:
Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439
*
a)Authors to whom correspondence should be addressed. Electronic mail: [email protected]
b)Electronic mail: [email protected]

Abstract

Rigid bodies provide a way to simplify the model used in a crystallographic refinement by removing parameters that describe degrees of freedom that are unlikely to change based on chemical experience. The GSAS software package provides a powerful implementation of rigid bodies that allows for refinement of classes of bond lengths, grouping of bodies to further reduce parameterization and where atomic motion can be described from group displacement parameters (TLS) representation. However, use of rigid bodies in GSAS is complex to learn and time-consuming to perform. This paper describes how the rigid body definition process has been simplified and extended through implementation in the EXPGUI interface to GSAS.

Type
Powder Diffraction Software
Copyright
Copyright © Cambridge University Press 2011

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References

Dinnebier, R. E. (1999). “Rigid bodies in powder diffraction: A practical guide,” Powder Diffr. 14, 8492.CrossRefGoogle Scholar
Finger, L. W., Kroeker, M., and Toby, B. H. (2007). “DRAWXTL, an open-source computer program to produce crystal structure drawings,” J. Appl. Crystallogr. 40, 188192.10.1107/S0021889806051557CrossRefGoogle Scholar
Larson, A. C. and Von Dreele, R. B. (2000). General Structure Analysis System (GSAS), Report LAUR 86-748, Los Alamos National Laboratory, Los Alamos, New Mexico.Google Scholar
Schomaker, V. and Trueblood, K. N. (1968). “On the rigid-body motion of molecules in crystals,” Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem. 24, 6376.10.1107/S0567740868001718CrossRefGoogle Scholar
Shahzad, A., Banck, M., Braithwaite, R., Bunt, J., Curtis, D., Fox, N., Hanwell, M., Hutchison, G., Jacob, B., Lonie, D., Mantha, J., Margraf, T., Niehaus, C., Ochsenreither, S., Tokarev, K., and Vandermeersch, T. (2011). Avogadro advanced molecular editor and visualizer <www.avogadro.openmolecules.net>..>Google Scholar
Swainson, I. P. and Brown, R. J. C. (1997). “Refinement of ammonium perrhenate structure using a pseudo-spin model for the ammonium ion orientation,” Acta Crystallogr., Sect. B: Struct. Sci. 53, 7681.10.1107/S0108768196011160CrossRefGoogle Scholar
Swainson, I. (2001). “The fireside guide to rigid bodies in GSAS <http://www.ccp14.ac.uk/ccp/web-mirrors/ian-swainson/fireside_fuide_to_rigid_bodies.pdf>..>Google Scholar
Toby, B. H. (2001). “EXPGUI, a graphical user interface for GSAS,” J. Appl. Crystallogr. 34, 210213.10.1107/S0021889801002242CrossRefGoogle Scholar