The formation of SiH+, PH+, and SH+ by radiative association

Cross sections for the radiative association of Si+, P+, and S+ with atomic hyrdrogen to form the diatomic molecular ions SiH+, PH+, and SH+, respecti vely, are presented. The results are obtained using fully quantum-mechanica l techniques and utilize ab initio molecular data calculated with the multi reference single- and double-excitation configuration-interaction (MRD-CI) method. Thermal rate coefficients are presented and applications of the res ults to diffuse interstellar clouds are discussed.