Extensive theoretical study on electronically excited states and predissociation mechanisms of sulfur monoxide including spin–orbit coupling

Abstract

The potential energy curves of the 69 Ω states generated from the 24 Λ-S states of sulfur monoxide are calculated for the first time using the internally contracted multireference configuration interaction method with the Davidson correction and the entirely uncontracted aug-cc-pV5Z basis set. Spin-orbit coupling is taken into account by the state interaction approach with the full Breit-Pauli Hamiltonian. Very good agreement is achieved between our computed spectroscopic properties and the available experimental data. The transition properties of the B(3)Σ(-) -X(3)Σ(-) and (4)1-X0(+) transitions are predicted, and our computed Franck-Condon factors and radiative lifetimes match the experimental results very well. The predissociation mechanisms are investigated, and various new predissociation channels are located. We present a new interpretation on the breaking-off of the rotational levels of the B(3)Σ(-) lower vibrational states observed in experiment, and propose that the predissociation is induced by the Coriolis coupling between the B(3)Σ(-) rovibrational levels and the A(3)Π state. Our calculations indicate that, at ν' = 9, the B(3)Σ(-) state predissociates via the C(3)Π state; around ν' = 14, three spin-orbit-induced predissociation pathways via (1)(5)Σ(+) , (2)(5)Π, and e(1)Π would be open; around ν' = 17, the pathways via (2)(1)Σ(+) , (2)(3)Σ(+) and (2)(5)Σ(+) would contribute. These satisfactorily explain the experimental results about the diffuseness of the B(3)Σ(-) bands. Furthermore, various predissociation pathways of the C'(3)Π state are predicted, through which the C'(3)Π state could predissociate rapidly.

Total Absorption Cross Section for UV Excitation of Sulfur Monoxide

“…In this study, we show new ab initio potential energy curves. On the basis of the reported results of other studies, both numerical and experimental, − ,− the spectroscopic constants from our study falls within the range of previously reported data. On the basis of the improved methodology of Danielache et al, we present high-resolution total absorption cross sections for the A 3 Π ← X 3 Σ – transition and two nonadiabatically coupled potential ([C 3 Π–C′ 3 Π] ← X 3 Σ – and [B 3 Σ – –3 3 Σ – ] ← X 3 Σ – ) transitions.…”

“…17 Elks and Western studied fluorescence, excitation lifetimes, and rotational constants on the A 3 Π state using multiphoton ionization techniques. 18 A computational work by Yu and Bian 19 analyzes the excited electronic state potentials and the spin−orbit coupling between them. The work by Borin and Ornellas analyzed the potential energy curves of low-lying singlet and triplet electronic states of SO 20 and A 3 Π ← X 3 Σ − transition.…”

Theoretical study of the vibrational excitation of SO(B3S

“…We start this discussion showing the spectroscopic parameters R e , D e , and w e of both SO(B 3 Σ − ) and ArS( 1 Σ + ) diatomic species. For comparison, also gathered in this same table are the results experimental and other theoretical [14,15]. All our results presented show good agreement with other works.…”

Line lists for the b1Σ+-X3Σ− and a1Δ-X3Σ− transitions of SO

“…Diode laser [ 15 , 16 ] and Fourier transform [17] vibration-rotation spectra are also available. The electronic structure of SO has also been investigated by means of ab initio calculations, e.g., [17][18][19][20][21] .…”