Region Style Prism

LAMMPS
1

image
image1748Ă—581 123 KB

For thermal conductivity calculation of Diamond (111), I have this triclinic structure.

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. For your kind reference, I am giving the details of my heat layers.
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heat layers

region hot_end prism 0 277.447 0 10 0 18.2376 249.70 0.0 0.0

region cold_end 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 hot prism 0 277.447 30 80 4 14 249.70 0.0 0.0
region cold prism 0 277.447 352 402 4 14 249.70 0.0 0.0

group hot region hot
group cold region cold

group hot_end region hot_end
group cold_end region cold_end
group end_one union hot_end cold_end

group fixed_heat_source_side region fixed_heat_source_side
group fixed_heat_sink_side region fixed_heat_sink_side
group end_two union fixed_heat_source_side fixed_heat_sink_side

group end union end_one end_two

compute Thot all temp/region hot
compute Tcold all temp/region cold

velocity all create $t 1198360
fix 1 all nvt temp $t $t 0.025
thermo 1000
run 200000
unfix 1
reset_timestep 0

fix 1 all nve

fix heatIN all ehex 1 2.30 region hot
fix heatOut all ehex 1 -2.30 region cold

velocity end set 0.0 0.0 0.0
fix set_end end setforce 0.0 0.0 0.0
"

I used prism style in region command for the triclinic system. Also, since I have a tilt in xy, I did not use INF for xlo, xhi, ylo and yhi. Rather I put specific values for them. After running the simulation, when the system equilibrates, the system temperature should be a constant value (in my case, I defined it to be around 300K). However, I cannot get the system to a constant tempeature, rather the temperature always increases exponentially till the last runsteps. Also, the source region should show higher temperature than the sink region but I am getting exactly opposite.

I am quite sure I am making some mistake in defining the region but I cannot seem to figure it out. Any help will be much appreciated.

2

image
image1906Ă—1273 295 KB

For more reference, I put different side views of my structure.

3

It would be better if you provided enough information for others to reproduce your results, rather than sharing only partial input. Additionally, your post is not properly formatted, and you haven’t specified your LAMMPS version.

Looking at your previous posts, this isn’t the first time the forum guidelines have been explained to you. If you continue to ignore these rules, it’s unlikely you’ll receive much assistance here:

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