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Nonrigid molecule effects on the energy levels of XeF 6
Author(s) -
Trindle C.,
Datta S. N.,
Bouman T. D.
Publication year - 1977
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.560110409
Subject(s) - raman spectroscopy , molecule , infrared , chemistry , energy (signal processing) , computational chemistry , relaxation (psychology) , chemical physics , atomic physics , molecular physics , physics , quantum mechanics , psychology , social psychology , organic chemistry
The geometric and electronic structure of XeF 6 is not yet fully understood, even though most of the means of structure determination available to the chemist have been employed in an effort to describe the molecule. We suggest that many of the experimental anomalies and theoretical difficulties arise from the possibility of rapid polytopal rearrangement in this system, and put forward in this report an analysis which accommodates the experimental data. We show that easy rearrangement produces substantial splittings in rigid‐molecule energy levels, and with the aid of Longuet‐Higgins group theory developed expressly for flexible molecules, compute energy‐level schemes for a set of plausible rearrangement modes. By appropriate choice of parameters specifying the extent of splitting, we match the reported infrared and Raman spectra, and their temperature dependence. The puzzling “time lag” in the Raman (but not the infrared) spectrum is tentatively ascribed to selective relaxation of Raman‐active vibrational modes.