The Tetrahedral X2YZ2 Molecular Model Part I. Classical Vibration Problem

Abstract

Appropriate coordinates are set up from the standpoint of group theory for describing the normal modes of oscillation in such a manner that maximum factorization of the secular determinant is accomplished. The cubic and quartic portions of the anharmonic potential function are derived. The components of vibrational angular momentum are set down. The complete valence‐type potential function is discussed; explicit relations are derived between the generalized force constants occurring in the secular determinant and the valence force constants for CH₂D₂.