Theoretical study of the electric dipole moment function of the ClO molecule

Abstract

The potential energy function and electric dipole moment function (EDMF) are computed for ClO X 2∏ using several different techniques to include electron correlation. The EDMF is used to compute Einstein coefficients, vibrational lifetimes, and dipole moments in higher vibrational levels. Remaining questions concerning the position of the maximum of the EDMF may be resolved through experimental measurement of dipole moments of higher vibrational levels. The band strength of the 1–0 fundamental transition is computed to be 12±2 cm−2 atm−1 in good agreement with three experimental values, but larger than a recent value of 5 cm−2 atm−1 determined from infrared heterodyne spectroscopy. The theoretical methods used include SCF, CASSCF, multireference singles plus doubles configuration interaction (MRCI) and contracted CI, coupled pair functional (CPF), and a modified version of the CPF method. The results obtained using the different methods are critically compared.