Multireference configuration interaction study on the potential energy curves and radiative lifetimes of low-lying excited states of CdH+ cation

Ab initio calculations on CdH+ cation have been performed with the high-level relativistic MRCI + Q method. The potential energy curves of seven low-lying Lambda-S states, correlated with the dissociation limits Cd+(S-2(g)) + H(S-2(g)), Cd(S-1(g)) + H+(S-1(g)), and Cd+(P-2(u)) + H(S-2(g)), are computed. And the accurate spectroscopic constants of the bound Lambda-S are determined. The permanent dipole moments (PDMs) of Lambda-S states as well as the spin-orbit matrix elements are evaluated. The results indicate that the abrupt changes of PDMs and the spin-orbit matrix elements are attributed to the change of the electronic configurations at the avoided crossing point. After considering the spin-orbit coupling (SOC) effect, the 12 Omega states generated from the Lambda-S states are investigated. It is indicated that the SOC effect is substantial for CdH+, leading to the double-well potential of (3)0(+) state. Finally, the transition properties of several transitions are reported, including the transition dipole moments, Franck-Condon factors, and radiative lifetimes. (C) 2014 Elsevier B.V. All rights reserved.