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 $n=2\mathrm{}$ 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.