Theoretical calculation of spectroscopy properties of selenium bromide cation

In this paper, the potential energy curves of 22 Λ-S states as well as 51 Ω states were calculated using the internally contracted multiconfiguration interaction and Davidson correction method. Through the obtained transition data, the spectroscopy data of the low excitation bound state are fitted and compared with the same main group ions. The phenomenon of avoided crossing that occurs in the Ω state is analyzed, and finally it is concluded that this phenomenon mainly occurs in the energy region between 20 000 cm^-1 and 40 000 cm^-1. The potential laser cooling transition cycle in the Ω state is analyzed. The Franck-Condon factor, radiative lifetime and Einstein coefficient between are calculated. In this paper, we argue that direct laser cooling of SeBr⁺ is not feasible. The content of our study provides a theoretical basis for subsequent calculations to explore the properties of SeBr⁺ spectrum.