Singlete−Hscattering at intermediate energies

Using Fredholm techniques employing only square-integrable basis functions, elastic $s$- and $p$-wave singlet electron—hydrogen—atom cross sections are calculated for the energy range 10-27 eV, that is, at energies where a continuum of open channels is present. The $s$ and $p$ amplitudes are combined with higher partial-wave amplitudes taken from earlier close-coupling results,to give singlet $e-\mathrm{H}$ elastic angular distributions at and above the ionization threshold.