Assessing the thermodynamic signatures of hydrophobic hydration for several common water models

摘要

Following the conclusions of an information theory analysis that hydrophobic hydration is dictatedby the equation of state of liquid water, we perform simulations of ten different water models toexamine the correlation between the fidelity of each model to the experimental density of liquidwater and the accuracy of its description of methane hydration. We find that the three- and five-pointwater models provide an inferior description of both the liquid density and methane solubilitycompared to the four-point water models. Of the four-point water models, TIP4P/2005 provides thebest description of both the aqueous equation-of-state and methane hydration thermodynamics.When the optimized potentials for liquid simulation united-atom description for methane is used, wefind that while the entropy and heat capacity of methane hydration are in excellent agreement withexperiment, the chemical potential and enthalpy are systematically shifted upwards. Wesubsequently reoptimize the methane interaction to accurately reproduce the experimentalsolubilities as a function of temperature by accounting for missing attractive interactions.