Effects of spin–orbit coupling on the electronic states and spectroscopic properties of diatomic SeS

Abstract

The electronic states and spectroscopic properties of selenium monosulfide (78Se32S) have been studied using relativistic configuration interaction methodology that includes effective core potentials of the constituent atoms. Potential energy curves of several spin-excluded (Λ−S) electronic states have been constructed and spectroscopic constants of low-lying bound Λ−S states within 5.1 eV are reported in the first stage of the calculations. In the next stage, the spin–orbit interaction has been incorporated and its effects on the potential energy curves and spectroscopic properties of the species have been investigated in detail. After the inclusion of spin–orbit coupling, the is identified as the spin–orbit (Ω) ground state of the species. The transition moments of several important dipole-allowed and spin-forbidden transitions are calculated and the radiative lifetimes of the excited states involved in the respective transitions are computed. Electric dipole moments (μz) for some low-lying bound Λ−S states as well as a few low-lying spin–orbit states (Ω-states) are also calculated in the present study.