The Vibration-Rotation Energies of Polyatomic Molecules Part II. Accidental Degeneracies

Abstract

The first- and second-order corrections to the vibration-rotation energies of polyatomic molecules are dealt with in instances where two or more vibration frequencies are accidentally degenerate. The method of the contact transformation employed in Part I is extended and made applicable to the two types of first-order resonance interactions, i.e., the Fermi-Dennison type and the Coriolis type. The components of the energy matrix are evaluated in general, and examples are considered to demonstrate how the actual energies may be evaluated.