Elastic Scattering of Low-Energy Electrons by Atomic Nitrogen and Atomic Oxygen

The phase shifts and elastic scattering cross sections of atomic nitrogen and oxygen for low-energy electrons have been calculated with central field potentials. Most emphasis has been placed on the Hartree-Fock potentials. In the low-energy range, the WBKJ approximation gives an indefinitely increasing cross section, whereas the integration of the differential equation yields finite cross sections in the limit of zero energy, for both nitrogen and oxygen. The Hartree potential does not allow for the existence of a bound state (negative ion) in either case. The Thomas-Fermi potential, although not reliable for low atomic numbers, does allow for the existence of a bound state (of approximately zero energy) in the case of oxygen.