A ‘first principles’ potential energy surface for liquid water from VRT spectroscopy of water clusters

Abstract

We present results of gas phase cluster and liquid water simulations from the recently determined VRT(ASP–W)III water dimer potential energy surface (the third fitting of the Anisotropic Site Potential with Woermer dispersion to vibration–rotation–tunnelling data). VRT(ASP–W)III is shown to not only be a model of high ‘spectroscopic’ accuracy for the water dimer, but also makes accurate predictions of vibrational ground–state properties for clusters up through the hexamer. Results of ambient liquid water simulations from VRT(ASP–W)III are compared with those from ab initio molecular dynamics, other potentials of ‘spectroscopic’ accuracy and with experiment. The results herein represent the first time to the authors' knowledge that a ‘spectroscopic’ potential surface is able to correctly model condensed phase properties of water.