MOLECULAR-DYNAMICS SIMULATION OF WATER PROPERTIES USING RWK2 POTENTIAL - FROM CLUSTERS TO BULK WATER

The accuracy of the two-body potential of Reimers et al. (RWK2, 1982) for water was evaluated by molecular dynamics simulation. As a test of this potential's ability to describe microscopic properties, the predicted structure, binding energy, and vibrational frequencies of clusters of various sizes are shown to agree remarkably well with available measurements and results calculated from first principle methods. The reliability of the potential was further tested via molecular dynamics simulation of the properties of bulk water for a range of intensive parameters of geochemical interest. The simulated PVT properties, liquid structure, self-diffusion coefficients, vaporization enthalpy, and power spectra all agree within a few percent with experimental data. Compared to the more frequently used TIP4P potential, the RWK2 potential is more accurate in the prediction of second virial coefficients and vibrational spectra, but not less accurate in other properties studied here.