Formation of SiO+ through radiative association of Si+(3s23p 2Pu) and O(2s22p4 3Pg)

Abstract

We investigate the radiative association of SiO+ in the collision of a Si+(3s23p 2Pu) cation and an O(2s22p4 3Pg) atom using the quantum mechanical method, including the cross sections and rate coefficients. We consider 18 dipole-allowed radiative association processes of SiO+. The results show that the 2 2Π → A 2Π transition contributes most for the SiO+ radiative association at temperatures from 10 to 10 000 K. The 2 2Π → X 2Σ+ and 2 2Σ− → A 2Π transitions are also relatively significant at high temperatures. The total rate coefficient is found to vary from 7.72 × 10−18 to 4.92 × 10−17 cm3 s−1. Finally, an analytical function is fitted to the total rate coefficient for the convenience of astrochemical modelling. The obtained cross sections and rate coefficients are expected to be useful for modelling the Si chemistry in the diffuse interstellar medium.