Resonant ion-pair formation in electron recombination with $\textHF^+$
The cross section for resonant ion-pair formation in the collision of low-energy electrons with HF+ is calculated by the solution of the time-dependent Schrödinger equation with multiple coupled states using a wave-packet method. A diabatization procedure is proposed to obtain the electronic couplings between quasidiabatic potentials of 1Σ+ symmetry for HF. By including these couplings between the neutral states, the cross section for ion-pair formation increases with about 2 orders of magnitude compared to the cross section for direct dissociation. Qualitative agreement with the measured cross section is obtained. The oscillations in the calculated cross section are analyzed. The cross section for ion-pair formation in electron recombination with DF+ is calculated to determine the effect of isotopic substitution.