Bound States in Screened and Bare Coulomb Potentials: A Nonorthogonal CI-Based Route to Effective Hamiltonians for Two-Electron Systems

摘要

One- and two-electron bound states in screened and bare Coulomb potentials are calculated by adopting a discretized multiconfiguration generator coordinate(GC) method which leads to an interactive nonorthogonal configuration interaction procedure with the optimization of GCs. The GCs are optimized wither by the method of simulated annealing or by a genetic algorithm. Critical scanning lengths for which bound states disappear in one-electron atoms are computed. A noninteracting model Hamiltonian for a two-electron atom based on the idea of screened Coulomb interaction is proposed and used for calculating electric dipole polarizability and establishing the threshold value of z for the appearance of autoionizing ground state of two-electron system.