Formation of phosphorus monobromide (PBr) and phosphorus monoiodide (PI) radicals through direct radiative association: Prospects for astrochemical environments

The cross sections and rate constants for the formation of phosphorus monobromide (PBr) and phosphorus monoiodide (PI) radicals through radiative association have been theoretically estimated using fully quantum mechanical methods. For temperatures ranging from 10 K to 15000 K, the thermal rate coefficients are found to vary from 2.86 × 10⁻²³ cm³⋅s⁻¹ to 1.20 × 10⁻¹⁸ cm³⋅s⁻¹ and from 7.73 × 10⁻²⁴ cm³⋅s⁻¹ cm³⋅s⁻¹ to 1.12 × 10⁻¹⁸ cm³⋅s⁻¹ for PBr and PI, respectively. Implications of PBr and PI radiative association to various astrochemical environments are briefly discussed.