I am using LAMMPS Documentation (2 Apr 2025 version).
For thermal conductivity calculation of Diamond (111), I have this triclinic structure (freestanding).
0.0 277.4474877 xlo xhi
0.0 432.49783068 ylo yhi
0.0 18.2376 zlo zhi
249.70273902 0.0 0.0 xy xz yz
The figure shows how I defined the source and sink regions. I used prism style in region command for the triclinic system and boundary condition is “p p p”. Also, since I have a tilt in xy, I did not use INF for xlo, xhi, ylo and yhi. The heat layers are:
’
region source_side_vacuum prism 0 277.447 0 10 0 18.2376 249.70 0.0 0.0
region sink_side_vacuum prism 0 277.447 422.498 432.498 0 18.2376 249.70 0.0 0.0
region fixed_heat_source_side prism 0 277.447 10 30 4 14 249.70 0.0 0.0
region fixed_heat_sink_side prism 0 277.447 402 422.498 4 14 249.70 0.0 0.0
region source prism 0 277.447 30 80 4 14 249.70 0.0 0.0
region sink prism 0 277.447 352 402 4 14 249.70 0.0 0.0
’
I am using EHEX thermostat to calculate thermal gradient. The heat flux amount is 0.001 eV/(ps-Angstrom^2). According to my region specification, the source side should have high temperature, and sink side should have low temperature. Also, the overall system should come to an equilibrium temperature. However, it is not reaching to an steady state in my case rather the temperature is exponentially increasing. Can anyone help me understand what might went wrong here?
I can provide more details, so kindly ask if you have any inquiry. Thanks.