Charge transfer processes in SiH 2+

Abstract

For SiH 2+ potential energy functions for the doublet and quartet electronic states resulting from the Si 2+y( 1S, 3P) + H( 2S) and Si +( 2P, 4P, 2D) + H + asymptotes have been calculated using CASSCF-CI electronic wavefunctions. At low collision energies the charge transfer reactions Si 2+ + H → Si + + H + are found to proceed via avoided crossing regions on the potential energy functions around R SiH = 10 bohr for the doublet states and around R SiH = 8 bohr for the quartet states. No such pathway connecting the metastable Si 2+( 3P) ion with the electronic ground state of the Si + ion was found. Spectroscopic constants and radiative transition probabilities for several low lying doublet and quartet states of SiH 2+ have been evaluated.