CONVERGENT MOLECULAR CLOSE-COUPLING CALCULATIONS FOR ION-ATOM COLLISIONS FROM LOW TO INTERMEDIATE ENERGIES

We propose a new scheme for molecular close-coupling calculations, in terms of a 'triple-centre' basis of adiabatic molecular orbitals, augm ented with a set of Gaussian pseudostates centred at a point between t he nuclei. The ability of this expansion to simultaneously reproduce e lectron excitation, capture and ionization is shown for He2+ +H(ls) an d H+ + H(ls) collisions. Convergence checks are performed to confirm t he accuracy of the results presented.