We extend the classical Polarizable Ion Model (PIM) to charged clays. We focus on Na-, Ca-, Sr-and Cs-montmorillonite with two types of structures for the octahedral sheet : trans-and cis-vacant. The full set of parameters of the force field is determined by density functional theory calculations, using maximally localized Wannier functions with a force-and dipole-optimization procedure. Simulation results for our polarizable force field are compared to the state-of-the-art non-polarizable flexible force field named Clay Force Field (ClayFF), in order to assess the importance of taking polarization effects into account for the prediction of structural properties. This force field is validated by comparison with experimental data. We also demonstrate the transferability of this force field to other aluminosilicates by considering faujasite-type zeolites and comparing the cation distribution for anhydrous Na, Ca, and Sr Y (and X) faujasites predicted by the PIM model and with experimental data.

Following our previous works on dry clays, we extend the classical Polarizable Ion Model (PIM) to hydrated dioctahedral clays, by considering Na-, Cs-, Ca-and Sr-montmorillonites in the mono-and bihydrated states. The parameters of the force field are determined by optimizing the atomic forces and dipoles on density functional theory calculations. The simulation results are compared with results obtained with CLAYFF force field and validated by comparison with experiment. The X-Ray diffraction patterns calculated from classical molecular dynamics simulations performed with the PIM force field are in very good agreement with experiments. We also demonstrate the transferablity of PIM force field to other aluminosilicates, here a faujasite-type zeolite compensated with Na + , with a significant improvement in cation locations compared to non-polarizable force fields.