Abstract
The two-state atomic-orbital expansion with variable effective charge is used to compute the variation with energy E and angle theta of the charge-exchange probability in H+-H collisions. The agreement with the experimental results of Helbig and Everhart (1965) is astonishingly good. Estimates are also made of the range of validity of the adiabatic approximation; considerable deviation from adiabatic conditions is found for E theta >1 keV deg.