thermal conductivity calculation problem with Lammps


These days i am calculating Argon thermal conductivity based on different temperature. I used the rNEMD method: fix thermal/conductivity, combined with fix/ave fix/time … everything according to the command manual and paper of Muller-Plathe .

But results show the values of themal-conductivity are almost a linear line(positive slope) increasing with time steps instead of horizontal line. What i expected is a horizontal line based on time steps. I double checked everything and didn’t find anything wrong. I post my input file in the attachment. Would anyone can give me some suggestions for the problem? I really appreciate that.



in.ArNEMD01.txt (1.56 KB)

Hi Eric,

Did your system reached thermal equilibrium? but I think most probably is your post-processing. I suggest double check your calculations according to the formula mentioned in MP’s paper.
Hope it helps.