Accurate spectroscopic constants of the lowest two electronic states in S-2 molecule with explicitly correlated method

作者：Wei, Changli; Zhang, Xiaomei; Ding, Dajun; Yan, Bing^*

来源：Chinese Physics B, 2016, 25(1): 013102.

DOI：10.1088/1674-1056/25/1/013102

• sulfur dimer
• MRCI-F12
• spectroscopic parameter
• core-valence correlation

A computational scheme for accurate spectroscopic constants was presented in this work and applied to the lowest two electronic states of sulfur dimer. A high-level ab initio calculation utilizing explicitly correlated multireference configuration interaction method (MRCI-F12) was performed to compute the potential energy curves (PECs) of the ground triplet X-3 Sigma(g) and first excited singlet a(1)Delta(g) states of sulfur dimer with cc-pCVXZ-F12(X = T, Q) basis sets. The effects of Davidson modification, core-valence correlation correction, and scalar relativistic correction on the spectroscopic constants were examined. The vibration-rotation spectra of the two electronic states were provided. Our computational results show excellent agreement with existing available experimental values, and the errors of main spectroscopic constants are within 0.1% order of magnitude. The present computational scheme is cheap and accurate, which is expected for extensive investigations on the potential energy curves or surfaces of other molecular systems.

• 出版日期2016-1
• 单位吉林大学