The Ramsauer-Townsend effect in methane

Abstract

Calculations are described which reproduce the well known Ramsauer-Townsend effect in the scattering of electrons by methane. The theoretical model used for the interaction of an electron with methane includes (i) the methane static potential, (ii) exchange effects which are approximated by orthogonalizing the incident wavefunction to bound wavefunctions of the same symmetry and (iii) a polarization potential which is chosen to give good agreement between theoretical and experimental total cross sections.