Path integral centroid molecular dynamics study of the dynamic structure factors of liquid para-hydrogen

The dynamic structure factors S(k, omega) of liquid p-H-2 in the range of 0.29 less than or equal to k less than or equal to 5.9 Angstrom(-1) have been calculated by means of a path integral centroid molecular dynamics simulation at 14.7 K and zero-pressure. The quantization of the nuclei has caused a red-shift of the spectrum of the phonon density of states owing to quantum dispersion. As in classical liquids, the calculated spectra of S(k,omega) clearly indicate the existence of the longitudinal acoustic-like mode and the de Gennes slowdown of structural relaxation at k = 2.0 Angstrom(-1). The sound velocity and the self-diffusion coefficient of p-H-2 agree well with the experimental values. (C) 1998 Elsevier Science B.V. All rights reserved.