THE INFRARED-SPECTRUM AND STRUCTURE OF HYDROGEN-FLUORIDE CLUSTERS AND THE LIQUID - SEMICLASSICAL AND CLASSICAL-STUDIES

Computer simulation methods are used to calculate the vibrational spectra of hydrogen fluoride clusters, and the liquid, in the intramolecular stretching region. A semiclassical approach, in which Monte Carlo and molecular dynamics simulations are analyzed using quantum vibrational calculations, is a considerable improvement over dipole correlation function methods. Comparisons with experimental data show that induced dipole interactions play an important role in determining spectral shifts. A simple Drude oscillator model of polarization allows the spectral shifts to be obtained correctly, but at the expense of overestimating structural correlations in the liquid.