A comparison of potential functions for molecular dynamic simulation of methane sorption in the silicalite

Simulation of physical processes

In order to make the best choice, two types of a force field have been studied to access a possibility of application of one of them to simulation of adsorption and transport processes in the silicalite (synthetic zeolite)-methane system. To accomplish this, the molecular dynamic technique implemented in the LAMMPS package was used. Priority criteria of the choice were retention of the structure completeness during long simulation runs, the system’s stability, the possibility of simulation of a separate good-sized zeolite cluster without using periodic boundary conditions for multiplying zeolite’s lattice in space. For the force-field, which met these requirements, some structural, thermodynamic and transport characteristics of the system were calculated. Radial and angular distribution functions for different atom pairs and triplets were obtained for both the pure zeolite and the silicalite-methane system. A good agreement of all obtained characteristics with literature data of numerical and natural experiments was achieved.