Extensive ab initio calculation on low-lying excited states of CCl+ including spin-orbit interaction

The entire 12 Λ-S states of CCl+ correlated to ground state atom C+ and Cl are calculated at scalar relativistic MRCI+Q/AV5Z level of theory. Spin-orbit interaction causes the 12 Λ-S states to split into 23 Ω states. The potential energy curves (PECs) of Λ-S and Ω states are depicted with the aid of the avoided crossing rule between the same symmetry. This is the first time that spin-orbit coupling (SOC) calculation has been carried out on CCl+. The spin-orbit coupling effect, leading to many avoided crossings, is found to be substantial for CCl+. The spectroscopic constants of the bound Λ-S and Ω states are determined, where a better agreement with experimental data is found. The predissociations for a3Π and A1Π induced by SOC are analyzed. Moreover, the transition properties, including transition dipole moments and Franck-Condon factors, are derived. Subsequently, the radiative lifetimes of transition a3Π0+-X1Σ+0+ and a3Π1-X1Σ+0+ are calculated.

► Spectroscopic constants for the 1Δ, 1Σ−, 1Σ+(II), 3Σ+(I), 3Δ, 3Σ−, 3П(II) and 1П(II) are firstly reported. ► The dissociation energies of the calculated electronic states are predicted in our work. ► It is first time that the entire 23 Ω states generated from the 12 Λ-S states have been studied. ► The predissociations for a3Пand A1П induced by SOC are firstly analyzed for CCl+. ► The transition properties including the TDMs, FC factors and radiative lifetimes are evaluated.