A New Method for Analyzing Powder Diffraction Patterns: Confirmation of a Predicted Phase of SF6
LAWRENCE S. BARTELL 1,
JACQUES C. CAILLAT 1, and
BRIAN M. POWELL 2
1 Department of Chemistry University of Michigan, Ann Arbor, MI 48109.
2 Neutron and Solid State Physics Branch, Atomic Energy of Canada, Ltd., Chalk River Nuclear Laboratories, Chalk River, Ontario K0J 1J0, Canada.
A recent computer simulation reproduced all of the solid-state transitions known for sulfur hexafluoride and predicted the unknown structure of its coldest phase. Subsequent neutron diffraction experiments that were performed to establish the structure of this phase could not be interpreted by conventional procedures. A method for analyzing Debye-Scherrer diffraction patterns was designed to avoid the many false minima that are encountered in standard analyses of low-symmetry phases. The structure found with this method confirmed the previous theoretical prediction.
Submitted on January 20, 1987
Accepted on April 14, 1987