Large-Scale Nanosecond Simulations of the Dynamics of the Xe + H2O System

Large-scale molecular dynamics simulations of the high-pressure transformations of the xenon/water system were performed involving special purpose molecular dynamics machines. We investigated several systems of different sizes and geometry at the suitable simulational conditions (density, temperature, etc.), which are similar to the experiments conducted on the xenon hydrates. A binary mixture (ice water + Xe) undergoes at high pressure a long evolution and the Xe-guest atoms, enclosed inside the water molecules, were observed and analyzed. Even for the thin slabs, starting with the capture of the guest atoms by the water molecules, the water clusters around the xenon atoms are formed. The results show that such a hydrate-like formation preserves its structural stability over a long period of the simulation time of order of nanosecond. The molecular dynamics simulations were performed on a basis of the MDGRAPE-2 modifications of the DL POLY general purposes package, with the efficient treatment of the Ewald real and reciprocal-space components of the Coulombic and Van der Waals forces. The MDGRAPE-2 accelerates the calculations of the Coulomb and Van der Waals forces, without applying a spherical cut of a fixed distance.