Theoretical study of charge exchange collisions between O22+ molecular ions and alkali atoms

A semiclassical multichannel approach has been used to calculate absolute cross-sections for charge exchange collisions between doubly charged molecular oxygen and alkali (Cs, K and Na) atoms at 12 keV. In the charge exchange reaction the n = 3, 4 Rydberg states of O₂⁺ are populated. The system is described as an active electron in the field of two inert cores. A one-centre description for the molecular oxygen core has been used. The present theoretical results agree with the available experimental data, while results from other two-state models do not. We show that there is population sharing among the final states during the collision and that the charge exchange reaction is not merely localized at curve crossings.