Generally, a unit cell of catalysts like zeolite contains hundreds of atoms. Thus, methods used for such calculation are sophisticated, such as periodic ab initio are computationally expensive and even impractical. However, recent developed hybrid methods, such as the embedded cluster or the combined quantum mechanics/molecular mechanics (QM/MM) methods can make it possible to calculate larger zeolite systems with much greater accuracy.15-17 Previously, we studied the N2O decomposition over Fe-FER, Fe-ZSM-5, Fe-BEA and Fe-FAU using ONIOM method.2 The results showed that the reactions occurred inside the pore of Fe-zeolite, while their zeolite frameworks have influence on both mechanism and energetics. For a calculation, the effect of zeolite framework is usually included in the reaction via van der Waals interaction.18,19 Recently, we studied the importance of the confinement effect from the zeolite framework for the adsorption process and reaction mechanism of hydrocarbon with a large quantum cluster using M06 functional.20-22 We found that M06 functional can represent the van der Waals from the zeolite framework well and can give accurate results in terms of reaction mechanism and energetic.