Comparison of experimental and theoretical electron-impact-ionization triple-differential cross sections for ethane

Abstract

We have recently examined electron-impact ionization of molecules that have one large atom at the center, surrounded by H nuclei (${\mathrm{H}}_{2}\mathrm{O}, \mathrm{N}{\mathrm{H}}_{3}, \mathrm{C}{\mathrm{H}}_{4}$). All of these molecules have ten electrons; however, they vary in their molecular symmetry. We found that the triple-differential cross sections (TDCSs) for the highest occupied molecular orbitals (HOMOs) were similar, as was the character of the HOMO orbitals which had a $p$-type ``peanut'' shape. In this work, we examine ethane (${\mathrm{C}}_{2}{\mathrm{H}}_{6}$) which is a molecule that has two large atoms surrounded by H nuclei, so that its HOMO has a double-peanut shape. The experiment was performed using a coplanar symmetric geometry (equal final-state energies and angles). We find the TDCS for ethane is similar to the single-center molecules at higher energies, and is similar to a diatomic molecule at lower energies.