Sum Rules for Vibrational—Rotational Energy Levels Including Centrifugal Distortion

Abstract

Sum rules are developed for the vibrational‐rotational energy levels of an asymmetric rotor. These sum rules contain the corrections for centrifugal distortion correct for terms of the order P⁴ in the Hamiltonian. If the P⁴ terms of the Hamiltonian are neglected these sum rules reduce to those derived for a rigid asymmetric rotor by Mecke.