Molecular-state close-coupling theory including continuum states. I. Derivation of close-coupled equations

摘要: We formulate a close-coupling theory of slow ion-atom collisions based on molecular (adiabatic) electronic states, and including the continuum. The continuum is represented by packet states spanning it locally constructed explicitly from exact states. Particular attention given to two fundamental questions: (1) Unbound electrons can escape local region spanned derive close-coupled integral equations correctly effects; ''propagator'' generated these does not conserve probability within basis. Previous molecular-state formulations give no account effects. (2) Nonadiabatic couplings adiabatic with same energy are singular, reflecting fact that an description behavior valid outside region. treat singularities show accurate representation nonadiabatic set well behaved. Hence basis-set be used describe close coupling in ''interaction region,'' provided effects included. In principle, formulation developed here extended large class model problems involving many-electron systemsmore » models for Penning ionization collisional detachment processes.« less