Complex-coordinate method.II. Resonance calculations with correlated target-state wave functions

We have computed the position and width of the $1s{\mathrm{}\left(2s\right)\mathrm{}}^2{}_{}{}^2{}_{}{}^{}S$ resonance of ${\mathrm{He}}^{-}$ using five different wave functions for the ground state of He. These wave functions include different amounts of spatial and angular correlation. The difference in the width using a closed-shell target-state function and a three-configuration target function with spatial and angular correlation is only 6.6%. The width using the former function is 12.55 meV, while that for the latter is 11.72 meV. We also performed the calculations without constraining the relative amplitudes of the configurations in the target function to those obtained from a variational calculation of the He ground-state energy. In these calculations we did not encounter the same instability of the complex energy as reported elsewhere in the literature. Finally, improvement in the target-state functions results in a convergence of the scattering-state energies towards the rotated rays. This is to be expected since the description of these states is dominated by the open channel.