Electronic excitation of oriented molecules by low-energy electrons: An application toH2

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 $X^1$ ${\Sigma }_g^{+}$→$b^3$ ${\Sigma }_u^{+}$ 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.