Mutual neutralization in low-energyH++F−collisions

Abstract

The cross section for mutual neutralization in collisions between ${\mathrm{H}}^{+}$ and ${\mathrm{F}}^{\ensuremath{-}}$ ions at low energies ($E\ensuremath{\leqslant}10$ eV) is calculated using a molecular close-coupling approach. Two different representations of the quasidiabatic potentials and couplings of HF are used. The effect of autoionization on the cross section is investigated. The coupled Schr\"odinger equation for the nuclear motion is solved using a numerical integration of the corresponding matrix Riccati equation and the cross section for mutual neutralization is computed from the asymptotic value of the logarithmic derivative of the radial wave function. The magnitude of the cross section for mutual neutralization in this reaction is small compared to other systems. This can be understood by the lack of avoided crossings at large internuclear distances. Resonant structures are found in the cross section and these are assigned with dominant angular momentum quantum number. The cross section for mutual neutralization in collisions of ${\mathrm{D}}^{+}$ and ${\mathrm{F}}^{\ensuremath{-}}$ ions is also calculated.