The Duschinsky Effect and Optical Spectra

Abstract

The influence of the normal mode rotation (i.e. the Duschinsky mixing) on the molecular electronic spectra in polyatomic molecules is treated by means of multidimensional intramolecular distributions (MID). It is shown that symmetry properties of the two-dimensional MID which relate emission and absorption spectra or pertain to the exchange of modes do not exist if the number of non-separable modes exceeds 2. Specific examples of emission band shapes are calculated for weakly (linear) coupled electronic states for both, zero and finite temperatures. The strength of the mixed quadratic interaction parameter is shown to influence the shape considerably. © 1983, Walter de Gruyter. All rights reserved.