Effect of vibration in electron scattering by H2 and D2

Total (elastic plus inelastic) differential scattering cross sections for 40-keV electrons incident on H2 and D2 have been measured with a precision of 0.1%. Theoretical scattering intensities as given by the independent-atom model are substracted from the experimental results and compared with two theoretical predictions. The calculations of Liu and Bonham, which utilize a poor wave function and a rather crude vibrational averaging, agree qualitatively with out results. The disagreement may be explained by considering the vibrational dynamics of the charge cloud of the molecules