Spectroscopic constants and spin-orbit coupling in the low-lying electronic states of AsBr

Abstract

In this work, ab initio calculations on the low-lying electronic states of arsenic bromide (AsBr) have been carried out using the internally contracted multi-reference configuration interaction with the addition of Davidson correction (icMRCI+Q) method. The potential energy curves (PECs) of the 34 Λ-S states and the 74 Ω states generated from the Λ-S states after considering the spin-orbit coupling (SOC) effects are calculated. The spectroscopic constants of the typical bound states have been calculated and are compared with available experiment results. With the calculated spin-orbit matrix element we analyze the SOC-induced predissociation mechanisms of the a1Δ and b1Σ+ states. The permanent dipole moments (PDMs), transition dipole moments (TDMs), Frank-Condon factors (FCFs) and radiative lifetimes of some low-lying states have also been acquired, which would be of value to understand the transition properties. Our study should enhance our understanding on the electronic structure and spectroscopy of AsBr molecule.