A molecular representation of Al3++H charge transfer reactions

Abstract

The charge transfer reaction Al3++H→Al2++H+ has been studied within a molecular representation appropriate for slow to intermediate velocity collisions. Ab initio electronic potential energy curves were computed for the lowest four 2Σ+ states of AlH3+, which dissociate to the limits Al3++H and Al2+(2S,2P0,2D)+H+. The configuration interaction wave functions were constructed to represent the four states in an unbiased fashion yielding asymptotic energy splittings within 1% of experimental values. Radial and dipole coupling matrix elements were obtained as a function of internuclear separation. Two formal criteria are proposed to evaluate the accuracy of the radial coupling elements which, in this case, were obtained through the Hellman–Feynman theorem. The nuclear scattering equations were solved in the semiclassical straight line trajectory approximation for the range of barycentric collision energies 0.01–1.0 keV/amu.