Ab initiostudy of charge-transfer dynamics in collisions of C2+ions with hydrogen chloride

Abstract

Ab initio quantum chemistry molecular calculations followed by a semiclassical dynamical treatment in the keV collision energy range have been developed for the study of the charge-transfer process in collisions of ${\mathrm{C}}^{2+}$ ions with hydrogen chloride. The mechanism has been investigated in detail in connection with avoided crossings between states involved in the reaction. A simple mechanism driven by a strong nonadiabatic coupling matrix element has been pointed out for this process. A comparative analysis with the halogen fluoride target corresponding to a similar electronic configuration shows a quite different charge-transfer mechanism leading to a very different behavior of the cross sections. Such behavior may be correlated to specific nonadiabatic interactions observed in these collision systems.