Explicitly correlated configuration interaction investigation on low-lying states of SiO ⁺ and SiO

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 14 Λ-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 B 2 Σ + 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 B 2 Σ + and A 2 Π is estimated. The laser cooling scheme of SiO + is proposed by employing B 2 Σ + -X 2 Σ + transition. Finally, the vertical ionization energy values from SiO (X 1 Σ + ) to ionic states: SiO + , X 2 Σ + , B 2 Σ + , and A 2 Π are calculated, which agree well with experimental measurements.

High-resolution laser-induced fluorescence spectroscopy of $^{28}$Si$^{16}$O$^+$ and $^{29}$Si$^{16}$O$^+$ in a cryogenic buffer-gas cell

“…By fitting the entire data with a Hamiltonian model, they have obtained more precise rotational and fine-structure constants for all three states. Along with the experimental studies, many theoretical calculations have been performed to investigate the potential energy curves and spectroscopic con-stants of the low-lying electronic states of SiO + [46,47,48,49,50,51,52,53,54].…”