Elastic Scattering of Low-Energy Electrons by the Hydrogen Molecule

Electron–H2 scattering at low energies is treated by an efficient numerical solution of the two-dimensional Schrödinger equation including the nonlocal exchange interaction. Correlation within the scatterer is included but polarization and short-range free–bound correlation are omitted. The elastic differential cross section is well described for scattering angles larger than about 30°–45°, and for energies up to at least 5 eV. The scattering function is analyzed in terms of spherical harmonics; the expansion is slowly convergent in the region 0.6–1 Bohr radii, with significant contributions as high as l = 10. The position of the observed broad resonance at about 3 eV is accounted for by the model in terms of the pσ wave, but it is inferred that free–bound correlation is necessary to account quantitatively for the width.