Calculation of Inelastic Electron—Molecule Collision Cross Sections by Classical Methods

We have used Thomson's, Gryzinski's, and Ochkur's classical methods for energy transfer in electronic collisions together with the quantum-mechanical Franck—Condon factor for the overlap of nuclear wavefunctions to compute inelastic electron—molecule collision cross sections. Specific application is to ionization and to direct and exchange electronic excitation. After first extending previous applications of the classical energy-transfer methods to atoms, we make calculations for ionization, direct and exchange (spin-change) excitation involving air molecules (N2, N2+, NO, O2, also CO). The results are applied to the near-threshold domain as well as to the over-all behavior of the cross section. Agreement with the very few absolute experimental data available is to within better than a factor of 2 to 3. These methods must be regarded as useful when one considers that there exist hardly any experimental data on excitation and that quantum-mechanical calculations would be prohibitively lengthy to carry out while the present calculations are very simple to perform.