Studies of Liquid Water by Computer Simulations. VI. Transport Properties of Carravetta–Clementi Water

Abstract

Abstract The micro canonical molecular dynamics simulations of liquid water were performed at different temperatures and densities in order to investigate the anomalies of the transport coefficients. The nonempirical Carravetta–Clementi potential was used for the system with 216 molecules in a cubic cell. The order of magnitude of the nonempirically calculated self-diffusion coefficient, shear viscosity, bulk viscosity, and thermal conductivity were in agreement with experimental results. These transport properties were recognized as anomalous as in real liquid water. The temperature-dependence of these quantities was in agreement with the observed values under pressure of 50 MPa. The effects of compression on these transport coefficients were reproduced qualitatively. The obtained bulk viscosity was larger than the shear viscosity at low temperatures in accordance with experiments. The contribution of rotational motion to thermal conductivity seems to be responsible for the anomalous temperature-dependence of thermal conductivity. Several decay constants of the time correlation functions were obtained. The frequency spectra of the correlation functions were discussed. No marked molecule number dependence was observed in the calculated transport coefficients of Matsuoka–Clementi–Yoshimine water.