A nonlinear model for highly excited vibrational energy levels of silane

The highly excited vibrational energy levels of SiH stretches of silane SiH4 in the electronic ground state are calculated using a three-parameter nonlinear model, i.e., the quantized discrete self-trapping equation. The obtained results are in good agreements with the experimental data and with those obtained from local mode calculations of others. We note that SiH4 molecule is a typical molecule close to the local mode limit, and that when n ≥ 3, the molecule could be thought of as vibrating with the four SiH stretching quanta trapped into a single SiH bond.