ir overtone spectrum of the vibrational soliton in crystalline acetanilide

The self-trapping (soliton) theory which was recently developed to account for the anomalous amide-I band at 1650 ${\mathrm{cm}}^{\mathrm{-}1}$ in crystalline acetanilide (a model system for protein) has been extended to predict the anharmonicity constant of the overtone spectrum. These infrared-active overtones which have been detected at 3250, 4803, and 6304 ${\mathrm{cm}}^{\mathrm{-}1}$ yield an anharmonicity constant that is in good agreement with the theory.