Charge-transfer processes in collisions of H+ ions with phosphorus atoms at low energies

We have carried out a theoretical investigation of charge transfer in collisions of H+ ions with neutral phosphorus P atoms bath in the ground and metastable states at collision energies below IO keV/u and above 100 eV/u using a molecular representation. Molecular states for the PH+ molecule are obtained by employing the ab initio multireference (single- and double-excitation) configuration-interaction method. In calculating charge-transfer cross sections, we have adopted the semiclassical impact-parameter method. The present charge-transfer cross sections from the ground-state P target are found to reach as large as 2x10(-15) cm(2) at 1 keV/u after slowly increasing from lower energies, and the contribution from P+(P-3) and P+(S-5(o)) formations to the total are found to be comparable at the energy region where the cross section possesses a maximum. [S1050-2947(99)07201-7].