Nonlinearly vibrational energy-spectra of molecular crystals

The nonlinear quantum vibrational energy spectra of amide-I in the molecula r crystals acetanilide are calculated by using the discrete nonlinear Schro dinger equation appropriate to this kind of crystals. The numerical results obtained by this method are in good agreement with the experimental values . Meanwhile, the energy levels at high excited states have also been obtain ed for the acetanilide, which is helpful in researching the Raman scatterin g and infrared absorption properties of the this kind of crystals.