Resonant charge transfer in symmetric alkali-ion–alkali-atom collisions

Resonant charge transfer in alkali-ion–alkali-atom collisions is investigated by using the molecular-orbital expansion method incorporating the use of electron translation factors. Molecular wave functions and eigenenergies are obtained by the pseudopotential method. Molecular properties, $R_e$, $D_e$, and ${\omega }_e$, obtained in the present calculation are in good accord with other recent theoretical results, as well as spectroscopic measurements. Three-state close-coupling calculations reproduce the positions of the maxima and minima in the oscillatory structure seen experimentally in the resonant-charge-transfer cross sections for the ${\mathrm{Li}}_2$ ${\mathrm{}}^{+}$ and ${\mathrm{Cs}}_2$ ${\mathrm{}}^{+}$ systems. The magnitude of the total cross sections and their velocity dependence are in agreement with experimental measurements.