Spectroscopic parameters and transition probabilities of several doublet and quartet states of sulfoxide cation

Abstract In this work, the potential energy curves of 11 doublet, 11 quartet, and 2 sextet states of a sulfoxide cation are reported and the transition dipole moments between them were calculated. The radiative lifetimes were on the order of 10–6 s for the A2Π, C2Π, b4Σ–, and 12Σ+ states, approximately 10–6 – 10–7 s for the 12Δ and B2Σ– states, and on the order of 10–7 s for the 22Σ+ state. The radiative lifetimes of these states were short, suggesting that the spontaneous emissions generated from them occurred readily. Many transitions are strong, including A2Π – X2Π, C2Π – X2Π, C2Π – A2Π, B2Σ– – X2Π, B2Σ– – A2Π, 12Δ – X2Π, 12Δ – A2Π, and b4Σ– – a4Π. In addition, the transitions from the the first well of the 12Σ+ state to the X2Π state, and from the first well of the 22Σ+ state to the X2Π, A2Π, and C2Π states, are also strong. These strong transitions were easy to measure through spectroscopy. The properties of the transitions between certain Ω states generating from the X2Π, A2Π, a4Π, and b4Σ– states were investigated, including several electric dipole–forbidden transitions. The A2Π1/2 – X2Π1/2, A2Π3/2 – X2Π1/2, b4Σ–3/2 – a4Π5/2, b4Σ–1/2 – a4Π1/2, and b4Σ–1/2 – a4Π3/2 transitions are strong. The radiative litimes of the A2Π1/2, A2Π3/2, a4Π–1/2, a4Π1/2, a4Π3/2, a4Π5/2, b4Σ–1/2, and b4Σ–3/2 states were calculated and the distributions of their radiative lifetime varying as rotational angular momentum quantum number J were studied. The radiative lifetimes of the a4Π1/2 and a4Π3/2 states are on the order of several ms; those of the a4Π5/2 state are approximately several–ten ms; while those of the a4Π–1/2 state are on the order of several s. The results calculated herein can provide some useful guidelines for further experimental and astronomical observations and theoretical studies.