On the semiclassical approach in the theory of ion–diatomic exchange interaction: its application to charge exchange reactions

An analytic study is presented of asymptotic properties of the three-center quasimolecular system A2(Za- 1)++BZb+ consisting of a homonuclear diatomic molecule and a highly charged atomic ion. The potential of the one-electron exchange interaction of this system is calculated asymptotically correctly (for large distances R between interacting particles) in the framework of the non-perturbative semiclassical and the Landau–Herring approaches. The total and state-selective n- and l-resolved cross sections of the electron capture in H2+Arq+ (q=6, 8, 14, 16) collisions in the energy region from 5.0 to 2×103 eV amu−1 were calculated and compared with available experimental and theoretical data. It is shown that with increasing projectile (atomic ion Arq+) charge, use of the semiclassical expression describing such an electron exchange interaction provides noticeably better (than with use of the Landau–Herring one) agreement between the calculated cross sections and experimental data.