Close-coupling calculations of differential cross sections for elastic scattering and rotational excitation of hydrogen molecules by electrons at 10 and 40 eV

We have performed close-coupling calculations including two rotational states for electron scattering by hydrogen molecules at 10 and 40 eV impact energies. The effective interaction potential was taken as a sum of the static, exchange, and polarization interactions. With no empirical parameters, good agreement with experiment was obtained for the angle dependences and magnitudes of the differentual cross sections for both pure elastic scattering and rotational excitation except that there are discrepancies in the elastic scattering at small scattering angles where the experiments are least reliable. Variations of the forms of the exchange and polarization potentials were examined and the effect on the cross sections was small.