Elastic scattering of electrons by methane molecules

Vibrationally elastic cross sections for electron collisions with CH₄ are calculated with an ab initio electrostatic potential. Effects of electron exchange and target polarization are taken into account approximately. Differential cross sections (DCS) are calculated for the electron energies 10-50 eV and compared with recent measurements. Comparing with the result of a spherical potential model, effects of anisotropy of the molecule are made clear. Integral and momentum-transfer cross sections are also calculated to see the validity of the extrapolation procedure taken in deriving those cross sections from experimental DCS.