Mean residence times and cage-to-cage migrations of CO<inf>2</inf> in ZIF-8 by molecular dynamics simulations

Abstract

Copyright © 2015 American Scientific Publishers. Molecular dynamic simulation has been employed to explore the cage-to-cage migration of CO2 in zeolitic imidazolate framework-8. The flexible framework is modeled by modified AMBER force field while the CO2-framework intermolecular interaction is modeled by ab initio fitted parameters. The obtained diffusion coefficients of CO2 molecules are in agreement with previous studies. The results show that the migrating CO2 molecules are located around the center of the six-ring window with nearly perpendicular orientation to the plane of the six-ring window. The molecular distributions, supercage mean residence times and the binding site mean residence times are obtained for more understanding the diffusion processes.