[lammps-users] temp/rescale

Steve,

I am studying thermal properties of nonlinear structure(triangular sheet of graphene). I am trying to create a temperature gradient at two ends by scaling the velocities of two ends using fix temp/rescale. Since it’s a triangular lattice, the no of atoms in both temp rescaled regions are not same. When i set the temperature of both ends to 300K, the heat current value is expected to be zero since there’s no temp diff as such between the two ends. But, in this case i am seeing a nonzero value for heat current. What does that mean??

Also, in the documentation, it’s mentioned that biasing is performed during temp/rescale. Does it mean that the center of mass velocity is being subtracted before scaling and then added after that??

Thanks
Ajit

But, in this case i am seeing a nonzero value for heat current. What does that mean?

I don't know. I don't see any reason it should be precisely 0.0.

Also, in the documentation, it's mentioned that biasing is performed during
temp/rescale. Does it mean that the center of mass velocity is being
subtracted before scaling and then added after that??

The doc page for fix temp/rescale says it "can" be used with a temp
that subtracts a bias. But if you didn't follow the instructions it gives,
then it won't. It doesn't by default.

Steve