Accurate spectroscopic calculations of the 19 Λ-S states and 36 Ω states of the BC+ cation

Abstract

ABSTRACTThis work computed the potential energy curves of 19 Λ-S states, which arose from the first five dissociation limits of BC+ cation, B+(1Sg) + C(3Pg), B+(1Sg) + C(1Dg), B+(1Sg) + C(1Sg), C+(2Pu) + B(2Pu), and B+(1Sg) + C(5Su). The calculations were done for internuclear separations from 0.08 to 1.07 nm. The potential energy curves of 36 Ω states yielded from these Λ-S states were also calculated. Core-valence correlation and scalar relativistic correction, basis set extrapolation as well as Davidson correction were accounted for. Of these Λ-S states, the c1Σ+, D3Π, 21Π, 23Σ+, 21Δ, 31Σ+, and 41Σ+ had double wells; the 33Π and 31Π states had three wells; the C3Σ− and D3Π states were inverted with the spin-orbit coupling effect included; and the second wells of c1Σ+, D3Π and 31Σ+ states, the second and the third wells of 33Π state as well as the third well of 31Π state were very weakly bound, which well depths were smaller than 400 cm−1. The spectroscopic parameters were determined for all the states. The vibrational properties were predicted only for some weakly bound states. The spin-orbit coupling effect on the spectroscopic parameters was evaluated.