Low-energy single-electron capture cross sections in C6+/C4+-Na(3s) and N7+/N5+-Na(3s) collisions: Molecular state approach

The low-energy state-selective capture cross sections for single-electron t ransfer from the ground state of Na(3s) atoms by fully (C6+ and N7+) and pa rtially stripped(C4+ and N5+) ions have been calculated using the semiclass ical approximation in the molecular orbital formulation augmented with the proper electron translation factor. The method of pseudopotential is invoke d to account for the interaction of the active electron with the moving nuc lei, whose relative motion is considered via a straight-line trajectory. Al though both C4+ and N5+ have identical He-like structure, their roles revea l very different collision dynamics. The projectile C4+ exhibits a distinct ive role due to its finite core; a low-energy structure in the total captur e cross section for C4+-Na(3s) collisions is observed and explained. For ba re projectiles (C6+ and N7+) there remains an increasing tendency of the St ark mixing to characterize the electron transfer processes; it enhances the population of the higher l states. The l distribution of the charge-transf er cross section for various projectile is also discussed. (C) 1999 John Wi ley & Sons, Inc. Int J Quant Chem 75: 385-398, 1999.