Spin-orbit calculations on SnBr: Potential energy curves, dipole moments and radiative lifetimes

Abstract

The electronic structures and spectroscopic properties of SnBr molecule are calculated by high-level multireference configuration interaction (MRCI) method. The Davidson correction (+Q) and spin-orbit coupling (SOC) effect are investigated in the calculations. The potential energy curves (PECs) of 23 Ʌ-S states and 45 Ω states generated from those Ʌ-S states are obtained. Based on the calculated PECs, the spectroscopic constants of the bound states are evaluated, which are in good accordance with previous experimental data. At the avoided crossing point, the dipole moments (DMs) of Ʌ-S states exhibit abrupt change, which are attributed to the change of electronic configurations of those states. With the help of the calculated SO matrix elements, the interaction between 14Σ- and nearby states is analyzed, and the possible predissociation pathway of low-lying vibrational levels of 14Σ- is illuminated. In the end, transition dipole moments (TDMs) and the radiative lifetimes from the excited states to the ground state are determined.