Cross sections for charge transfer, neutralization and excitation in H-H and H- -H+ collisions are presented in the energy range 1-30 keV. The semiclassical close-coupling approach is used with a two-centre two-electron atomic state expansion and frozen total spin. All details of the two-centre atomic state expansion scheme are given. The basis is expanded onto the bound state of H- and the two-centre H(1s)-H(nlm ) states, where n covers the K, L and M shells. A good agreement with experiments is achieved for charge transfer, neutralization and excitation to H(2s) in H-H collisions. Disagreement with previously published close-coupling calculations and experimental data is noted, especially for two-electron charge transfer in H- -H+ .

Differential collision results based on classical (CTMC) and quantal (AOCC) calculations for single-electron capture in collisions of He 2+ projectiles with oriented Na(3p −1 ) atoms are compared at three intermediate impact energies (velocities of 0.45, 0.86 and 1.21 au). Good agreement between the two methods is reported with respect to the total capture probability, differential cross section and left/right scattering asymmetry. The polarization interaction with the target is so strong that the repulsive scattering in the final capture channels is seen only at the highest energy as a direct correspondence of left-/right-hand side trajectory results and left-/right-hand side scattering results. State-to-level and state-to-state capture results reveal differences between the predictions of classical and quantal methods.