Abstract
Ab initio calculations are presented for several states of He2+ and Li2+ that are relevant to collision problems. In He2+, qualitative agreement is found with the predictions from the analysis of the oscillations and anomalous thresholds in He+-He collision cross sections. For Li2+, the results suggest that the oscillations in Li+-Li differential scattering cross sections are due to ΣΠ transitions caused by the coupling of electronic and nuclear rotations.