Multireference configuration interaction study of the 27 low-lying states of the PF+ cation

Abstract

This paper studied the spectroscopic parameters and vibrational properties of 27 Λ-S and 60Ω states of PF+ cation. The 27 Λ-S states were the X2Π, A2Σ+, B2Π, C2Σ−, D2Δ, a4Σ−, b4Π, c4Σ+, d4Δ, 22Σ+, 32Σ+, 42Σ+, 22Σ−, 32Σ−, 32Π, 42Π, 52Π, 62Π, 22Δ, 32Δ, 12Φ, 24Σ−, 34Σ−, 24Π, 34Π, 16Σ−, and 16Π, which were generated from the first four dissociation limits. The 60Ω states were produced from the 27 Λ-S states. All the potential energy curves were calculated with the CASSCF method, which was followed by the icMRCI+Q approach. The a4Σ−, b4Π, and D2Δ states were inverted with the spin-orbit coupling effect accounted for. The 24Π, 24Σ−, 22Δ, 32Δ, 32Σ+, 42Σ+, 12Φ, and 22Σ− states were repulsive whether the spin-orbit coupling effect was included or not, but the 52Π and D2Δ states became repulsive only with the spin-orbit coupling effect included. The C2Σ− state was very weakly bound. The a4Σ− state had one barrier. The avoided crossings existed between the a4Σ− and 24Σ− states, the 22Σ+ and 32Σ+ states as well as the D2Δ and 22Δ states. Core-valence correlation and scalar relativistic corrections were taken into account. The extrapolation to the complete basis set limit was done. The spectroscopic parameters and vibrational properties were determined. The transition dipole moments were calculated and the Franck-Condon factors of some electric dipole transitions were evaluated. The spin-orbit coupling effect on the spectroscopic and vibrational properties was discussed.