The thermodynamics and structure of liquid water

Abstract

The additive interatomic interaction model has been used to calculate the thermodynamic functions of liquid water. The O … O and H … H nonbonded interactions were described by Kitaigorodsky potential functions of type 6-exp; for the H … O interactions the hydrogen bond potentials were introduced, and refined using sublimation heats of ice modifications and the normal vibrations of the water dimer. The thermodynamic functions of liquid water were obtained by averaging the corresponding thermodynamic quantities by the Monte Carlo method in the NVT ensemble. Different initial configurations were considered and the results were proved to converge, provided the Markov chain is sufficiently long. The calculated thermodynamic functions were in agreement with the experimental data. An analysis of instantaneous equilibrium configurations was carried out, and conclusions were drawn to what degree the previously proposed structures of liquid water correspond to reality.