Critical point and coexistence curve for a flexible, simple point-charge water model

Abstract

The pressure of simulated water was determined at 130 state points spanning a wide range of densities (15–773 kg m −3) and temperatures (473–1073 K) from molecular dynamics simulations using a flexible, simple point-charge water model. These data were fitted to an equation of state, which was then used to determine the coexistence curve using the double tangent construction. The calculated critical temperature and density for this water model were 604.3 K and 269.4 kg m −3, as compared to 647.1 K and 322 kg m −3 for real water. Properties calculated from molecular simulations using this water model can now be compared with the properties for real water at the same reduced conditions.