Numerical study of autoionizing states in completely correlated two-electron systems

Abstract
The structure of a one-dimensional two-electron model atom analogous to helium is examined. Predictions of Hartree-Fock and basis-state diagonalization methods are compared with results of exact numerical techniques. Particular attention is given to the lowest-energy autoionizing resonance and to how the autoionizing state can be defined. The dynamics of the autoionizing decay are examined with regard to the time development of the spatial wave function and various population amplitudes. The photoabsorption line shape of the lowest-lying autoionizing state for dipole excitation from the first excited state is also presented.