Application of the noniterative-integral-equation method to electron-hydrogen scattering

A noniterative-integral-equation method (NIEM) is successfully applied to $S$-wave scattering of electrons by atomic hydrogen. Reactance-matrix elements and partial-wave cross sections are computed for energies above and below the $n=2$ threshold. The results are stable despite the strong degenerate dipole coupling between the $2s$ and $2p$ channels. In addition, it is demonstrated, by locating the first $^{1}S$ resonance, that the NIEM works in the resonance region below threshold.