Molecule opacities of , , and states of CS+**Project supported by the National Key Research and Development Program of China (Grant Nos. 2017YFA0402300 and 2017YFA0403200), the National Natural Science Foundation of China (Grant Nos. 11474032, 11534011, U15302611, and 1404180), and China Postdoctoral Science Foundation (Grant No. 2018M631404).

Abstract

Carbon sulfide cation (CS+) plays a dominant role in some astrophysical atmosphere environments. In this work, the rovibrational transition lines are computed for the lowest three electronic states, in which the internally contracted multireference configuration interaction approach (MRCI) with Davison size-extensivity correction (+Q) is employed to calculate the potential curves and dipole moments, and then the vibrational energies and spectroscopic constants are extracted. The Frank–Condon factors are calculated for the bands of and systems, and the band of is in good agreement with the available experimental results. Transition dipole moments and the radiative lifetimes of the low-lying three states are evaluated. The opacities of the CS+ molecule are computed at different temperatures under the pressure of 100 atms. It is found that as temperature increases, the band systems associated with different transitions for the three states become dim because of the increased population on the vibrational states and excited electronic states at high temperature.