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

Abstract

Complete Active Space Self Consistent Field (CASSCF) with Multireference Configuration Interaction (MRCI) and Rayleigh-Schrodinger Perturbation Theory (RSPT2-RS2) methods have been used to investigate the potential energy curves for the 12 low-lying singlet and triplet electronic states in the representation 2s+1 Λ (+/-) of the molecule BaS with Davidson corrections. The harmonic frequency w e , the internuclear distance R e , the electronic energy with respect to the ground state T e , the rotational constants B e and the permanent dipole moment have been calculated for these electronic states. The eigenvalues E v , the rotational constants B v , the centrifugal distortion constant D v and the abscissas of the turning points R min and R max have been investigated using the canonical functions approach. Nine new electronic states have been investigated here for the first time. The comparison between the values of the present work and those available in the literature for several electronic states shows a good agreement.