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diffusion length calculation

Posted: Fri Aug 03, 2012 11:08 am
by mikhail.otrokov
Dear all,

I am a newcomer in diffusion issues and maybe my question is quite naive, but is it possible to calculate diffusion length using AKMC code? If it is not, do you have any suggestions how to do this?

Thanks in advance!

Best regards,

Misha

Re: diffusion length calculation

Posted: Fri Aug 03, 2012 12:49 pm
by graeme
You can make a plot of distance^2 vs time for a diffusing species during an AKMC simulation. The slope will give you the diffusion constant. Alternatively, you can discover the diffusion mechanism(s) and use the Einstein–Smoluchowski relation to calculate the diffusion constant from the hopping distance and rate(s).

Re: diffusion length calculation

Posted: Sat Aug 04, 2012 9:02 am
by mikhail.otrokov
Dear Graeme,

Thank you very much for your reply! What is a maximum number of atoms which can be treated using AKMC? I suspect that this number is restricted by VASP capabilities, but not sure.

Thanks in advance!

Best regards,

Misha

Re: diffusion length calculation

Posted: Sat Aug 04, 2012 2:35 pm
by graeme
There is no hard limit. Certainly with DFT, the cost will increase rapidly with system size.

Re: diffusion length calculation

Posted: Sat Aug 04, 2012 6:04 pm
by mikhail.otrokov
Thaks a lot, Graeme! I'll try to calculate something )