Currently there are no reliable theoretical approaches for calculating fully differential cross sections (FDCS) for low-energy electron-impact ionization of large molecules. We have recently introduced the distorted-wave impulse approximation as a first step in developing improved theoretical approaches. One significant obstacle to evaluating improved theoretical approaches which require significant computer resources lies in the fact that the existing experimental data require taking averages over all molecular orientations. To circumvent this problem, it has been proposed to approximate the orientation-average by using an orientation-averaged molecular orbital in the calculation of the FDCS. The theoretical justification and expected range of validity for the approximation is given in this paper. Examples are presented for electron-impact ionization of H2 and N2.
J. Gao et al., "An Elementary Method for Calculating Orientation-Averaged Fully Differential Electron-Impact Ionization Cross Sections for Molecules," Journal of Chemical Physics, American Institute of Physics (AIP), Jan 2005.
The definitive version is available at http://dx.doi.org/10.1063/1.2118607
Keywords and Phrases
Electron Impact Ionisation; Hydrogen Neutral Molecules; Molecule-Electron Collisions; Orbital Calculations
Library of Congress Subject Headings
Article - Journal
© 2005 American Institute of Physics (AIP), All rights reserved.