Novel model for calculating the intermolecular part of the infrared spectrum for molecular complexes

An approach for including the intermolecular part of the zero-point vibrational energy in the calculations of intermolecular interactions is presented. The approach is applied to the water complexes of water, ammonia, dimethyl ether, formaldehyde, formamide, acetone and formic acid adopting a model potential. Effects on structure, interaction energy and intermolecular vibration frequencies are discussed. The model is successful in predicting the experimental far infrared spectra, and provides further insights in the assignment of these spectra.