Electronic excitation of oriented molecules by low-energy electrons: An application to H2

We report inelastic differential cross sections for electronic excitation of an oriented molecule by low-energy electrons. Specifically we look at the dependence of these cross sections for the ${X}^{1}$${\ensuremath{\Sigma}}_{g}^{+}$\ensuremath{\rightarrow}${b}^{3}$${\ensuremath{\Sigma}}_{u}^{+}$ transition in ${\mathrm{H}}_{2}$ on both incident and scattered angles as well as on impact energy. These electron scattering cross sections exhibit a pronounced dependence on the incident and scattered angles, which suggests that related electron-energy-loss spectroscopy studies can be a useful probe of adsorbate-substrate structure.