A Spectroscopic Description of Asymmetric Isotopologues of CO₂

Abstract

A polyad-conserving algebraic model applied to vibrational excitations of asymmetric isotopologues of CO 2 is presented. First, the problem of vibrational excitations is studied by taking into account only the minimum subspace of states to characterize the Fermi interaction. This analysis allows an estimation of the force constants as well as the feasibility of describing the system in a local mode scheme, in terms of SU( 2) operators associated with Morse ladder operators for the stretches. This description together with the algebraic U(3) for the bends establishes the dynamical group SU 1 (2) × U(3) × SU 2 (2) for a series of isotopologues. Six isotopologues are considered, namely, 16