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

✍ Scribed by Le Yu; Wensheng Bian

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 296 KB
• Volume: 32
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.21737

✦ Synopsis

The potential energy curves of the 69 X states generated from the 24 L-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 S 2 -X 3 S 2 and (4)1-X0 1 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 S 2 lower vibrational states observed in experiment, and propose that the predissociation is induced by the Coriolis coupling between the B 3 S 2 rovibrational levels and the A 3 P state. Our calculations indicate that, at m 0 5 9, the B 3 S 2 state predissociates via the C 3 P state; around m 0 5 14, three spin-orbit-induced predissociation pathways via (1) 5 S 1 , (2) 5 P, and e 1 P would be open; around m 0 5 17, the pathways via (2) 1 S 1 , (2) 3 S 1 and (2) 5 S 1 would contribute. These satisfactorily explain the experimental results about the diffuseness of the B 3 S 2 bands. Furthermore, various predissociation pathways of the C 03 P state are predicted, through which the C 03 P state could predissociate rapidly.