Formation of SiO⁺ through radiative association of Si⁺(3s²3p ²P_u) and O(2s²2p^{4 3}P_g)

¹ Optics and Thermal Radiation Research Center, Institute of Frontier and Interdisciplinary Science, Shandong University, 72 Binhai Road, Qingdao 266237, PR China
e-mail: z.qin@sdu.edu.cn
² School of Energy and Power Engineering, Shandong University, 27 Shanda Nanlu, Jinan 250061, PR China
³ School of Energy Science and Engineering, Harbin Institute of Technology, 92 Xidazhi Street, Harbin 150001, PR China

Received: 29 October 2022
Accepted: 10 February 2023

Abstract

We investigate the radiative association of SiO⁺ in the collision of a Si⁺(3s²3p ²P_u) cation and an O(2s²2p^{4 3}P_g) 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.