Structure and Dynamics of Water at the Water-Air Interface Using First-Principles Molecular Dynamics Simulations within Generalized Gradient Approximation.

Abstract

First-principles molecular dynamics simulations within the density functional theory framework have been used to predict the surface structure of water at various aqueous interfaces, but there is no clear consensus on the choice of appropriate simulation parameters, such as exchange-correlation functions and van der Waals corrections yet. Here, we report the systematic survey for the structure and dynamics of water at the water-air interface simulated with various combinations of the exchange-correlation functionals within the generalized gradient approximation and empirical dispersion corrections. Particularly, we focus on the structure and dynamics of the free O-D group of D2O, as well as the surface tension of water. Through the comparison of these quantities with the experimental and accurate force field calculations, we conclude that revPBE with van der Waals correction shows significantly better results for simulating various air-water interfacial properties than BLYP and PBE functionals.