An ab initio study of the 11A2 state of BCl2+: the emission spectrum

Ab initio calculations have been performed on the X 1ϵg+, 11B2 and the 11A2 states of the boron dichloride cation. Geometry optimizations and harmonic vibrational frequency calculations were carried out on the 11A2 state using the CIS, MP2, CCSD(T) and CASSCF methods. Adiabatic and vertical deexcitation energies were also calculated for transitions to the ground electronic state of the cation (1ϵg+), with the highest level of theory being CCSD(T)/6-311G(3df) and MRSD-CI/TZV2P. These calculations suggest that it is possible that the 11A2 state is responsible for an emission seen in synchrotron photoelectron experiments, probably via vibronic coupling.