Abstract
Classical three-body calculations have been performed to predict total and doubly differential ionisation probabilities and cross sections for 10 keV to 100 MeV H++H and 100 keV H++He collisions. Total and differential electron capture cross sections have been calculated from 3 keV to 1 MeV for H++H. The results are in good agreement with measured cross sections and with other theoretical results known to be relatively good approximations in specific impact energy regimes. The validity of the classical approximation especially at high projectile velocities is discussed.