Accurate calculations on 12 Λ-S and 28 Ω states of BN+ cation: Potential energy curves, spectroscopic parameters and spin-orbit coupling

The PECs of 28 Ω states generated from the 12 electronic states of the BN+ cation are studied for the first time. The 16Σ−, 32Π and A4Π are found to be the inverted states. Each of the 12Σ+, 22Π, 32Π and 22Σ− states possesses the double well. The PECs are calculated by the CASSCF method followed by the icMRCI approach. The core-valence correlation and scalar relativistic corrections are included. The convergence of present calculations is found with respect to the basis set and level of theory. The SO coupling effect is accounted for by the state interaction method with the Breit-Pauli Hamiltonian. The PECs are extrapolated to the CBS limit. The spectroscopic parameters are evaluated. The present spectroscopic parameters can be expected to be reliably predicted ones. The effect of SO coupling on the spectroscopic parameters is not obvious almost for all the electronic states involved here.