Vibration-rotation effects on properties of symmetric tops and linear molecules

Abstract

An expression is derived for the expectation value of an electronic property P in an arbitrary vibration-rotation state of (i) a symmetric top and (ii) a linear molecule. P is represented by a property surface in reduced normal coordinates. The formula, valid to first order of perturbation theory, is derived both by a contact transformation and by arguments based on the Hellmann-Feynman theorem.