Dear MS users,

I am trying to validate the CH4 diffusion in ZIF-8 using dreiding force field. In the literature,CH4 diffusivity is reported as nearly 10^-6 cm2/sec when ZIF-8 is considered as flexible. However, I found very low diffusion coefficient for CH4 (10^-9 cm2/sec) . I used dreiding force field for CH4 and ZIF-8. What can be the reason for this difference between diffusivities? Do I have to change dreiding force field for ZIF-8?

I will be appreciate for any helpful answer.

Best

İlknur