Charge transfer and ionization in collisions ofSi3+with H from low to high energy

Abstract

Charge transfer processes due to collisions of ground state ${\mathrm{Si}}^{3+}(3s\phantom{\rule{0.3em}{0ex}}^{1}S)$ ions with atomic hydrogen are investigated using the quantum-mechanical molecular-orbital close-coupling (MOCC) and classical-trajectory Monte Carlo (CTMC) methods. The MOCC calculations utilize ab initio adiabatic potentials and nonadiabatic radial coupling matrix elements obtained from Herrero et al. [J. Phys. B 29, 5583 (1996)] which were calculated with a full configuration-interaction method. Total and state-selective single-electron capture cross sections are obtained for collision energies from $0.01\phantom{\rule{0.3em}{0ex}}\mathrm{eV}∕\mathrm{u}$ to $1\phantom{\rule{0.3em}{0ex}}\mathrm{MeV}∕\mathrm{u}$. Total and state-selective rate coefficients are also presented for temperatures from $2\ifmmode\times\else\texttimes\fi{}{10}^{3}\phantom{\rule{0.3em}{0ex}}\mathrm{K}$ to ${10}^{7}\phantom{\rule{0.3em}{0ex}}\mathrm{K}$. Comparison with existing data reveals that the total CTMC cross sections are in good agreement with the experimental measurements at the higher considered energies and that previous Landau-Zener calculations underestimate the total rate coefficients by a factor of up to two. The CTMC calculations of target ionization are presented for high energies.