Spin-orbit coupling effects in the spectroscopy and predissociation of the low-lying states of germanium monobromide

In this work, the electronic structure of GeBr is investigated by high-level multireference configuration interaction (MRCI) method plus Davidson correction ( + Q). To improve the accuracy of the computations, the core-valence (CV) electrons correlations, and spin-orbit coupling (SOC) effect are considered. The po-tential energy curves (PECs) of 23 low-lying states correlated with the lowest three dissociation limits are obtained, as well as those of 45 ? states originated from the 23 low-lying states. The spectroscopic constants of low-lying states are obtained, which are in agreement with the available experiments. The abrupt variations of dipole moments (DMs) are attributed to the change of the electronic configurations in the avoided crossing regions. Based on the computed PECs of the electronic states and SO matrix elements, the predissociation pathway of the vibrational levels of 4 ?- and 2 ?( 11 ) sates are discussed. Finally, the transition dipole moments (TDMs), Franck-Condon factors (FCFs), and radiative lifetimes of A2 ?+-X2 ?, 2 ?( 11 )-X2 ?, 1/2( B )-X2 ?1/2, 1/2( 11 )-X2 ?1/2, X2 ?3/2-X2 ?1/2, and 3/2( B )-X2 ?1/2 transitions are estimated.& COPY; 2023 Elsevier Ltd. All rights reserved.