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

¹ Physics Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6372, U.S.A. e-mail: stancil@mail.phy.ornl.gov
² Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996-1200, U.S.A.
³ Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138, U.S.A. e-mail: kkirby@cfa.harvard.edu
⁴ Theoretische Chemie, Bergische Universität-Gesamthochschule Wuppertal, Gaußstr. 20, D-42097 Wuppertal, Germany e-mail: jgu@ist.ucf.edu, buenker@wrcs1.urz.uni-wuppertal.de
⁵ Department of Chemistry, Indian Institute of Technology, Kharagpur 721 302, India

Send offprint request to: P.C. Stancil

Received: 19 July 1999
Accepted: 23 November 1999

Abstract


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