A new paper in Marivi’s collaboration with Fabiano Corsetti, Emilio Artacho, José M. Soler and S. S. Alexandre has been accepted to Journal of Chemical Physics of AIP. In this work, “Room temperature compressibility and the diffusivity anomaly of liquid water from first principles” is calculated using ab initio molecular dynamics simulations of 200 molecules at five densities. These simulations include non-local correlations using van der Waals functionals without empirical parameters. They have decided to use two different type of van der Waals functionals: vdW-DFPBE functional and VV10 functional and they compare these results with previous findings from PBE and vdW-DF functionals.
It is shown that both functionals predict compressibilities within ~30% of experiment, while only vdW-DFPBE functional correctly predicts the the density dependence of the self-diffusion constant and its anomalous behavior. While vdW-DFPBE functional describes the high-density structures of water, VV10 functional describes the low-density structures of water with good precision. Overall, vdW-DFPBE functional currently gives the best description of the liquid water.