Neutralisation in H⁺+H⁻collisions

A two-centre expansion in travelling atomic orbitals is employed to investigate H + -H - collisions at energies at and above 8 keV (lab) for which electron exchange between the hydrogen atoms formed in the neutralisation reaction is unimportant. In addition to the H + +H - channel, terms representing H(n=2)+H(1s) and H(n=3)+H(1s) are included in the wavefunction together with a number of pseudostate orbitals designed to overlap the hydrogenic continuum. The calculated cross sections are in agreement at high energies with previous calculations based on a one-electron model by Ermolaev (1985), and also agree quite well at 8-10 keV with the data of Gaily and Harrison (1970).