Absorption spectrum of the a(E '(2g))<- X(G '(g)) and b(G '(g))<- X(G '(g)) electronic transitions of ReF6

The absorption spectra of the near-infrared and ultraviolet bands of ReF6 h ave been recorded with a commercial spectrophotometer. The vibronic assignm ents previously published by different authors are critically revised. A no n-perturbative method has been used to calculate the linear Jahn-Teller lev els for the nu(5) mode in the ground electronic state. Some new vibronic pa rameter values are derived. The nu(5) linear Jahn-Teller parameter in the X (G(g)') electronic state is found to be D-5 = 0.103(9). The ultraviolet abs orption spectrum has enabled us to determine relatively accurate values of the crystal-field (10Dq) and spin-orbit (zeta(d)) parameters. (C) 1999 Else vier Science B.V. All rights reserved.