Low-energy electron scattering by silane (SiH₄)

Vibrational and electronic excitation of SiH 4 has been investigated for low-energy electrons in the energy range 1-25 eV. Vibrational excitation of the X 1 A 1 ground electronic state is dominated by a 1 eV broad shape resonance around 2.1 eV, which induces excitation of the n nu 1,3 vibrational series (Si1H stretching motion) and of the n nu 1,3 nu 2,4 series (Si1H stretching with one quantum of angular deformation). Valence electronic excitation is obtained in small-momentum-transfer conditions (0.2<K<0.5 au). A tentative unified assignment for excitation of the core (Si 1s, Si 2p) and of the outermost valence (2t 2 ) orbitals is proposed in terms of excitation to a common manifold of virtual valence and Rydberg orbitals.