Accurate spectroscopic calculations of the 22 Λ-S states and 60 Ω states of the PS+ cation

This work studied the PECs of 22 Λ-S states, which were yielded from the first two dissociation limits of PS+ cation. The PECs were calculated using the CASSCF method, followed by the icMRCI + Q approach. Core-valence correlation and scalar relativistic corrections as well as basis set extrapolation were included. Only the 35Σ+ state was repluse without the SOC effect, but the 35Σ+, 15Δ, 25Σ+, and 15Σ− states were repulse with the SOC effect included. The 23Π and 21Π states had double wells, but the first well of 23Π state had no vibrational levels and the first well of 21Π state had only one vibrational state. The avoided crossings were found between the 11Π and 21Π states and between the d3Π and 23Π states. The 25Σ+, 15Π, 15Δ, b3Δ, and c3Σ− states were inverted with the SOC effect accounted for. The spectroscopic properties were evaluated. The vibrational levels of some states and Franck-Condon factors of some transitions were determined. The SOC effect on the spectroscopic results was discussed. Analyses show that the spectroscopic parameters obtained can be expected to be reliably predicted ones.132