Explicitly correlated configuration interaction investigation on low-lying states of SiO+ and SiO**Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0402300), the Science Challenge Project (Grant No. TZ2016005), the China Postdoctoral Science Foundation (Grant No. 2018M631404), the National Natural Science Foundation of China (Grant No. 11404180), the University Nursing Program for Yong Scholars with Creative

Abstract

SiO+ and SiO, which play vital roles in astrophysics and astrochemistry, have long attracted considerable attention. However, accurate information about excited states of SiO+ is still limited. In this work, the structures of 14Λ–S states and 30 Ω states of SiO+ are computed with explicitly correlated configuration interaction method. On the basis of the calculated potential energy curves of those Λ–S states and Ω states, the spectroscopic constants of bound states are evaluated, which are in good agreement with the latest experimental results. The predissociation mechanism of state is illuminated with the aid of spin–orbit coupling matrix elements. On the basis of the calculated potential energy curves and transition dipole moments, the radiative lifetime for each of low-lying vibrational states and is estimated. The laser cooling scheme of SiO+ is proposed by employing transition. Finally, the vertical ionization energy values from SiO ( to ionic states: SiO+, , , and are calculated, which agree well with experimental measurements.