A general purpose model for the condensed phases of water: TIP4P/2005

TLDR

TIP4P/2005 is a rigid four‑site model comprising three fixed point charges and one Lennard‑Jones center. The authors present a general‑purpose potential model for the condensed phases of water. The model was parametrized by fitting the temperature of maximum density (derived from the melting point of hexagonal ice), ice polymorph stabilities, and other key targets, and it predicts a wide range of thermodynamic properties—including densities, phase diagrams, dielectric constants, pair distribution functions, and self‑diffusion—across 123–573 K and up to 40 000 bar. The model delivers impressive accuracy across diverse properties and conditions, achieving an average density error of only 7 × 10⁻⁴ g cm⁻³ at 1 bar with a maximum density at 278 K.

Abstract

A potential model intended to be a general purpose model for the condensed phases of water is presented. TIP4P/2005 is a rigid four site model which consists of three fixed point charges and one Lennard-Jones center. The parametrization has been based on a fit of the temperature of maximum density (indirectly estimated from the melting point of hexagonal ice), the stability of several ice polymorphs and other commonly used target quantities. The calculated properties include a variety of thermodynamic properties of the liquid and solid phases, the phase diagram involving condensed phases, properties at melting and vaporization, dielectric constant, pair distribution function, and self-diffusion coefficient. These properties cover a temperature range from 123to573K and pressures up to 40000bar. The model gives an impressive performance for this variety of properties and thermodynamic conditions. For example, it gives excellent predictions for the densities at 1bar with a maximum density at 278K and an averaged difference with experiment of 7×10−4g∕cm3.