For the first time, the spectroscopy and transition properties of SeCl + are systematically reported. The potential energy curves of 22 Λ − S states and the corresponding 51 Ω states in the first and second dissociation channels of SeCl + are calculated using the internally contracted multiconfiguration interaction and Davidson correction method. The phenomenon of avoided crossing in Ω states below 30,000 cm −1 is discussed in detail. The spectroscopy constants are obtained by fitting the potential energy curves, and also the Franck− Condon factors and radiation lifetimes of the X 3 Σ 0 + − ↔ 2 1 Σ 0 + + transition are calculated. Between X 3 Σ 0 + − and 2 1 Σ 0 + + , the Franck−Condon factors are large, close to 1, but the radiation lifetime is large too. According to the calculation results, it is determined that direct laser cooling of SeCl + is considered infeasible.

No abstract

In this paper, potential energy curves of Λ−S and Ω states of SBr + are reported for the first time, and the spectrum data of some low excited bound states are obtained. The differences in the spectrum properties of main-group molecules and SBr + were compared and analyzed, providing a sufficient theoretical basis for the subsequent study of main-group molecules. The 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 and 40,000 cm −1 that is relative to the minimum energy value. Potential transitions in the Ω state capable of achieving laser cooling of SBr + are explored. The Franck−Condon factor, radiation lifetime, and Einstein coefficient between X 3 Σ 0 + − and b 1 Σ 0 + + are calculated. From the calculation results, we concluded that direct laser cooling of SBr + is not feasible. What we have studied in this paper provides a theoretical basis for subsequent computational exploration of the spectrum properties of SBr + .