Theoretical Investigation of Complex Potentials for Atomic Collisions. I. Numerical Solution of Model (H−,H) Collisions

A set of coupled equations for rearrangement collisions involving processes such as scattering, electron transfer ($A^{-}+B\to A+B^{-}$), collisional detachment ($A^{-}+B\to A+B+e$), and associative detachment ($A^{-}+B\to AB+e$) is solved numerically for the (${\mathrm{H}}^{-}$,H) collision system at low energies. In this calculation, the interaction potential between the ground states of H and ${\mathrm{H}}^{-}$ is approximated by a set of local complex potentials. The energy dependence and scattering-angle dependence of the electron-detachment and electron-transfer probabilities, and of differential cross sections for scattering, electron transfer, and detachment processes, are calculated. A detailed analysis of the interference structures in the various differential cross sections is made for the diffraction and multipath scatterings, and for the gerade-ungerade and nuclear symmetry interferences. The effect of damping due to the imaginary parts of the complex potentials and the effect of isotope substitutions are investigated. To examine the sensitivity of the calculated results to the potentials adopted, the calculations are carried out for several sets of such complex potentials. Important differences, which may provide useful information for further investigations, are found for different sets of potentials.