Hi everybody

As i know the calculation of diffusion of gas molecules in polymeric membrane is as follows:

D= slop of (MSD vs Time)/6

or

MSD= at+b

D=a/6

Is there another method?

In the attached file (a part of one paper, 2014), as i bold, the calculation is different. The slop for the CO2 is 0.1323 and calculated D is 1.32 * 10^-8. Does any one know how it can be true?