These effects of spin–orbit coupling, core–valence correlation and scalar relativistic correction on spectroscopic calculations for PN+ cation

Abstract

The potential energy curves (PECs) of 9 Λ-S states (X2Σ+, 14Σ+, 16Σ+, A2Π, 14Π, 16Π, 14Δ, 14Σ−, 24Π) and corresponding 28 Ω states of PN+ cation are calculated by the complete active space self-consistent field (CASSCF), which is followed by the internally contracted multireference configuration interaction (icMRCI) with Davidson modification. The calculation is taken into account these effects of spin–orbit coupling, core–valence correlation and scalar relativistic correction. These are found that the 24Π, 16Π and 14Σ− states possess double wells and two avoided crossings occur between the 16Π and 26Π states, the 24Π and 34Π states. Based on the PECs, the spectroscopic parameters are evaluated. And the transitions (transition dipole moments, Franck–Condon Factors and radiative lifetimes) from 16Π−1/2 and 24Π−1/2 (the first well of the two states) to the ground state X2Σ+1/2 are obtained in this paper. These effects of spin–orbit coupling, core–valence correlation and scalar relativistic correction on the spectroscopic calculations are analyzed.