dc.creator Rey, M. en_US dc.creator Boudon, V. en_US dc.creator Loete, M. en_US dc.date.accessioned 2006-06-15T20:23:02Z dc.date.available 2006-06-15T20:23:02Z dc.date.issued 2002 en_US dc.identifier 2002-RC-07 en_US dc.identifier.uri http://hdl.handle.net/1811/20459 dc.description $^{a}$R. S. McDowell and L. B. Asprey J. Mol. Spectrosc. 45, 491-493 (1973). $^{b}$M. Rey, V. Boudon, M. Lo\""{e}te and F. Michelot J. Mol. Spectrosc. 204, 106-119 (2000). $^{c}$M. Rey, V. Boudon and M. Lo\""{e}te J. Mol. Struct. 599, 125-137 (2001). $^{d}$M. Rey, V. Boudon, M. Lo\""{e}te, P. Asselin, P. Soulard and L. Manceron J. Chem. Phys. 114(24), 10773-10779 (2001). $^{e}$V. Boudon, M. Rotger, Y. He, U. Schmitt, H, Hollenstein and M. Quack, submitted for publication. en_US dc.description Author Institution: Laboratoire de Physique de l'Universit\'{e} de Bourgogne, UMR CNRS en_US dc.description.abstract The rhenium hexafluoride ($ReF_{6}$) molecule has the particularity to possess an incomplete electronic d subshell. This open-shell system belongs to the $O_{h}$ group and exhibits a very large spin-orbit coupling leading to a fourfold degenerate electronic ground state of symmetry $G^{\prime}_{g}$. This implies complex couplings between electronic and nuclear motions (vibronic couplings) and between electronic, nuclear and rotational motions (rovibronic couplings) which considerably complicate calculations. Many years ago, some abnormalities in the spectrum of the triply degenerate $\nu_{3}$ band of symmetry $F_{1u}$ (the absence of the usual PQR pattern for such an isolated band, for instance) was attributed to a dynamical quadratic Jahn-Teller $effect^{a}$. But all the theoretical vibronic models developed up to now give matrices with very large sizes when adding the rotational part and this leads in practice to inextricable problems. To solve this, we propose a systematic tensorial development in the $SU(2) \otimes C_{I} \supset O^{S}_{h}$ group chain for the construction of the effective rovibronic $Hamiltonian^{b,c}$. This new theoretical model is based on a polyad scheme and allows a simultaneaous treatment of the four vibronic sublevels $F_{1u} \otimes G^{\prime}_{g}=E^{\prime}_{1u} \oplus E^{\prime}_{2u} \oplus 2G^{\prime}_{u}.$ The corresponding rovibronic energies are obtained by block-diagonalizing the full Hamiltonian for the considered vibronic polyad. The size of each rovibronic block is thus finite. In a previous study, we have successfully tested this model for an electronic triplet state $(V(CO)_{6})^{d}$. Here, we report in a similar way the low resolution band profile of the $\nu_{3}$ band of $ReF_{6}$ and show the agreement between the $observed ^{e}$ and calculated spectrum. en_US dc.format.extent 354438 bytes dc.format.mimetype image/jpeg dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title ROVIBRONIC COUPLINGS IN A FOURFOLD DEGENERATE ELECTRONIC STATE OF AN OCTAHEDRAL MOLECULE: THE $\nu_{3}$ BAND OF $ReF_{6}$. en_US dc.type article en_US
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