Equations of state and phase coexistence properties for simulated water

There is a practical need in modeling both ambient and high-temperature water near and above the critical point with a single transferable intermolecular potential. Thermodynamic properties for two water potentials, the simple point charge (SPC/E) and the polarizable point charge (PPC) models, are examined with the aid of molecular dynamics simulations. Analytical equations of state, liquid-vapor coexistence properties and critical point parameters are given. The effect of applying an external electric field to the system on the coexistence properties is investigated. A shift of the critical point of water to higher temperature and pressure is observed, a result similar to that of the introduction of an electrolyte to water. (C) 2001 Elsevier Science B.V. All rights reserved.