Theoretical Calculation of the Low-Lying Electronic States of the Molecule PbO

Abstract

The potential energy curves of the lowest 20 electronic states in the representation 2s+1 Λ (±) of the molecule PbO have been investigated via ab initio CASSCF and MRCI (single and double excitations with Davidson correction) calculations. The spectroscopic constants such as vibrational harmonic frequency ω e , the internuclear distance at equilibrium R e , the rotational constant B e , and the electronic transition energy T e with respect to the ground state have been calculated along with the permanent dipole moment for the different bound investigated electronic states. By using the canonical functions approach, the eigenvalues E v , the rotational constant B v and the abscissas of the turning points R min and R max have been calculated. The comparison of these values with those available in the literature shows a very good agreement.