Elastic scattering of electrons by methane molecules

Vibrational elastic, rotationally summed cross sections for electron collisions with CH₄ are calculated with ab initio static-exchange interactions and using a symmetry-adapted, single-center-expansion representation for the close-coupling equations. The correlation forces are included through density-functional theory and via a near-Hartree-Fock self-consistent-field description of the target wave function. Integral and differential cross sections are calculated over a broad range of collision energies, from the shape resonance region up to 50 eV. Comparisons with experiments and with previous calculations show that the present results indeed exhibit very good overall accord with measurements at these collision energies and describe very efficiently the electron angular distributions as given by a very broad range of measurements.