Total potentials of intermolecular interaction and low-frequency vibrational spectra of liquids

The development of a new approach, previously proposed by the authors, for estimating the frequency of intermolecular vibrations in liquid systems, based on direct calculation of the force constant by determination of the second derivative of the total interaction potential in a liquid, is presented. Direct correlation between the values of these frequencies and thermodynamic properties of single-component liquids is established for the first time. Using a number of nonpolar and polar liquids as an example, it is shown that, for the most part, calculated frequencies of intermolecular vibrations are in good quantitative agreement with the experiments. 17 refs., 2 figs., 2 tabs