Classification of Rotational Energy Levels for Linear Molecules

Abstract

The classification of the rovibronic energy levels according to the symmetry species of the molecular point group, previously presented only for nonlinear molecules, is extended to linear molecules, within the approximation that the interaction between rotational and vibronic motions can be neglected. Selection rules in terms of these species are obtained for the rovibronic transitions. The effect of the rotation—vibronic interaction on the classification scheme and the selection rules is considered.