I have written my fix to calculate the diffusion of the concentration, linked below if anyone has some time for inspection (would be grateful!)
I am having problem with setting the boundary, instead of being fixed (f), I want it to be periodic instead. It seems like I have some troubles communication for the atoms at the boundary. How should I go around to fix it?
new fix style mentioned:
and input script:
changing either the x-dimension or the y-dimension from f to p will give wrong simulation result...