Molecular dynamics simulations have been carried out to provide an atomic description of the behavior of naphthalene and anthracene in NaX zeolite. The force field parameters, which were selected in this process, were chosen carefully to examine dependence of the self-diffusion coefficient of sorbates over a wide range of loading, temperature, and pressure. The simulated adsorption isotherm and calculated adsorption energies at low concentration were found to be in a reasonable qualitative and quantitative agreement with the corresponding scarce experimental data which can evaluate the effectiveness of proposed calculation method and force field parameters. The simulations provided new insights into the simulated concentration dependence of the atomic behavior of bi and tri aromatics inside NaX micropores. Collective effects of the mutual interactions of sorbates molecules competing for the most preferable sites at the super cages (SCs) were found to be key factors responsible for the observed behavior of the adsorption isotherms, heat of adsorption, activation energy, and self-diffusivity. All involved calculations were performed in time period 6 ns and repeated calculations have been done at least two times to confirm the results and use the average values, which made the results being reliable.

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