Molecular Dynamics Simulation of Liquid Water

Abstract

Abstract A molecular dynamics simulation has been performed for a fluid system containing 1000 water molecules confined to a cubical box at mass density 1 g cm−3, where the ST2 type intermolecular potential has been used. Newtonian equations of motion of molecules were solved according to the method of constraints proposed by Ryckaert et al. Atomic radial distribution functions and corresponding partial structure functions at 24 and 93 °C were given and compared with theoretical calculations for the pentamer–monomer mixture model and neutron diffraction data. The agreement among the three was found to be satisfactory on the whole. In order to investigate how profoundly the periodic boundary condition influences upon the calculated values, the difference between the hydrogen-bonding behavior of molecules near the boundary and that of those in the central part of the box was examined into details. The population of hydrogen bonds near the boundary was found to be about 10% lower than that in the central part including about 210 molecules. In addition to these static properties the self-diffusion process was investigated.