Various total cross-sections for electron impact on C2H2, C2H4 and CH3X (X = CH3, OH, F, NH2)

Cross-sections for the impact of electrons having energy E-i = 50-5000 eV are evaluated fur polyatomic molecules C2H2, C2H4, C2H6, CH3OH, CH3F and CH3NH2. Total (complete) cross-sections and total inelastic cross-sections are calculated fur these targets by employing the atomic optical potentials and additivity rules. A variant of our previous work, to be called MAR-SC has been developed for molecules such as the present ones, where two approximately independent scattering centres can be identified. We find a good general accord of our theoretical values with various experimental data. Also given presently is an analytical fit Q(T) = A (alpha(o)/E-i)(B), incorporating polarizability alpha(o), for the high energy total cross-sections for 18-electron targets. Tentative upper and lower limits for the electron molecule total ionization cross-sections are identified and a break-up into elastic and inelastic contributions is exhibited.