Evaluation of various water models for simulation of adsorption in hydrophobic zeolites

We have performed a molecular simulation study on water adsorption in hydrophobic zeolites. The framework structures are truly periodic and therefore the Ewald summation is the natural choice for computing the Coulombic interactions. However, a few water models have been parameterised using this method. The adsorption results are extremely sensitive to the water model used, the framework positions in the orthorhombic structure and the atomic charges of the zeolite framework. This work provides insight into the identification of the potential limitations of the available force fields and models, and into the point charges used for the zeolite atoms, when they are applied to a highly hydrophobic system. We discuss feasible routes to conciliate simulation and experimental results.