Low-energy scattering of electrons from SiH₄ molecules

The calculations are performed in the static-exchange formalism using a spherical approximate target wavefunction. The exchange interaction is treated in three different ways: exactly within the spherical model (EE), by means of a modified semiclassical exchange (MSCE) potential and by combining the MSCE potential with an orthogonalisation procedure (OMSCE). A parameter-free model correlation-polarisation potential is included to represent the interactions not considered in the pure static-exchange approximation. Elastic total and momentum transfer cross sections are reported for e-SiH₄ scattering in the energy range 0.05-20 eV. The adequacy of the MSCE potential and the effects of the orthogonalisation on the final results are analysed by comparing the results obtained by the three methods. The error induced by the spherical approximation is estimated by comparing the present OMSCE results with those obtained without the sphericalisation.