THE PATTERN OF CLUSTERS IN ISOLATED VIBRATIONAL COMPONENTS OF CF4 AND THE SEMICLASSICAL MODEL

The semiclassical model for the rotation of molecules is used to interpret the rotation-vibrational energy level diagram of CF4. The definition of the model is sharpened, partly by means of the splitting of the energy levels into vibrational components and partly by introducing limitations in the possible shapes of the classical rotational energy surface. The model is used to discuss the pattern of clusters in each manifold of energy levels. The appearance of clusters in series of 6-fold, 8-fold, 12-fold, and 24-fold clusters is explained. It is also shown that folded series are a simple consequence of the model. The pattern of clusters in isolated vibrational components as a function of J is discussed with special attention to a rather common reversal of the pattern of clusters. On the basis of the possible qualitative changes in the shape of the rotational surface, these reversals are shown to appear only in two types. the simple inversion and the complex inversion. By means of examples, the details of both kinds of inversion are shown to be in full agreement with the qualitative requirements of the model. Finally, a quantitative application of the model to the vibrational ground state is presented. © 1993 Academic Press, Inc.