Question about NVT as a hot/cold reservoir

Dear Lammps Users,

When I try to investigate the thermal conductivity of graphene, I want to try the NEMD method by integrating hot/cold reservoir with NVT ensemble, and the sample with NVE to reach a steady T gradient. However, I can’t figure out how to get the value of heat flow.
By reading NVT’s instruction, I find

  • PE_eta[tchain] = potential energy of each particle thermostat displacement (energy units)
  • KE_eta_dot[tchain] = kinetic energy of each particle thermostat velocity (energy units)
    I wonder if I should sum these six terms (for tchain=3 as default), and devided by the timestep to get the heat flow (or say the power of heat bath)?

I know the other 4 methods and just want to try this one.
Any suggestions will be appreciated.
Thank you very much.

Sincerely,
Yuan Gao

Dear Lammps Users,

When I try to investigate the thermal conductivity of graphene, I want to
try the NEMD method by integrating hot/cold reservoir with NVT ensemble, and
the sample with NVE to reach a steady T gradient. However, I can't figure
out how to get the value of heat flow.
By reading NVT's instruction, I find

PE_eta[tchain] = potential energy of each particle thermostat displacement
(energy units)
KE_eta_dot[tchain] = kinetic energy of each particle thermostat velocity
(energy units)

I wonder if I should sum these six terms (for tchain=3 as default), and
devided by the timestep to get the heat flow (or say the power of heat
bath)?

i just answered the very same question in response to a different
e-mail with the same question (is that a coincidence?).
please check that response.

axel.

Thank you very much.