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First-principles molecular dynamics simulations, in which the forces are computed from electronic structure calculations, have great potential to provide unique insight into structure, dynamics, electronic properties, and chemistry of interfacial systems that is not available from empirical force fields. The majority of current first-principles simulations are driven by forces derived from density functional theory with generalized gradient approximations to the exchange-correlation energy, which do not capture dispersion interactions. We have carried out first-principles molecular dynamics simulations of air-water interfaces employing a particular generalized gradient approximation to the exchange-correlation functional (BLYP), with and without empirical dispersion corrections. We assess the utility of the dispersion corrections by comparison of a variety of structural, dynamic, and thermodynamic properties of bulk and interfacial water with experimental data, as well as other first-principles and force field-based simulations. [ABSTRACT FROM AUTHOR]

A research addressing a comprehensive particle-based simulation study of the structural, dynamic, and electronic properties of the liquid-vapor interface of water utilizing both ab initio and empirical models is illustrated. Numerous properties such as interfacial width, hydrogen bond populations, dipole moments, and correlation times will be characterized with identical schemes to draw useful conclusions on the strengths and weakness of the proposed models for interfacial water.

First principles Monte Carlo simulations in the Gibbs and isobaric–isothermal ensembles were performed to map the vapor–liquid coexistence curves of methanol and methane described by Kohn–Sham density functional theory using the Becke–Lee–Yang–Parr (BLYP) exchange and correlation functionals with the Grimme correction term for dispersive (D2) interactions. The simulations indicate that the BLYP-D2 description with the TZV2P basis set underpredicts the saturated vapor densities and overpredicts the saturated liquid densities and critical and boiling temperatures for both compounds. Although the deviations are quite large, these results present a significant improvement over the BLYP functional without the correction term, which misses the experimental results by a larger extent in the opposite direction. Simulations at one temperature indicate that use of the larger QZV3P basis set may lead to improved saturated vapor densities, but not to significant changes in the liquid density. [ABSTRACT FROM AUTHOR]