# Need help in thermal conductivity calculation

Hello everyone,
I am Ehsan Khaled, a PhD researcher in University of New South Wales, Australia. I am using LAMMPS as my MD simulation software. Currently, I am in the primitive stage and just doing some simulations for bulk silicon.

Q.1: I have found examples/kappa that include four different script to calculate thermal conductivity. I was just wondering can you refer me to scripts for a metal with tersoff or SW potential in real units. The unit conversion from lj to real or SI seems to be quite complex.

Q.2: Moreover, is there any LAMMPS code developed for calculating thermal conductivity of Sapphire/corundum? or at least the lattice of sapphire is developed?

Q.3: Is there any potential file developed for corundum or sapphire? If yes, where I can find them? If no, how to develop potentials from scratch?

Thanks for your help in advance. your help will give me a good start of my study.

PhD Candidate
School of Mechanical & Manufacturing Engineering
The University of New South Wales
NSW 2052, Australia
+61450882609

Hello everyone,
I am Ehsan Khaled, a PhD researcher in University of New South Wales,
Australia. I am using LAMMPS as my MD simulation software. Currently, I am
in the primitive stage and just doing some simulations for bulk silicon.

Q.1: I have found examples/kappa that include four different script to
calculate thermal conductivity. I was just wondering can you refer me to
scripts for a metal with tersoff or SW potential in real units. The unit
conversion from lj to real or SI seems to be quite complex.

the scripts are for illustration. don't use them in a "black box" kind
of way. in order to do meaningful simulations and get reliable
results, you have to *understand* the entire process and check that
what you are doing is correct at each step. you will need to study
relevant publications and refer to suitable text books. what you are
after is a complex calculation with many parameters and many system
dependent choices. this can only be done through careful
experimentation and learning what causes errors at the individual
steps. relative to that, tracking down how to convert units is a
trivial issue and you'll get to that almost automatically.

Q.2: Moreover, is there any LAMMPS code developed for calculating thermal
conductivity of Sapphire/corundum? or at least the lattice of sapphire is
developed?

please see the published literature. and for hard materials, you
should also study the impact of impurities. as mentioned above, this
is no black box procedure.

Q.3: Is there any potential file developed for corundum or sapphire? If yes,
where I can find them? If no, how to develop potentials from scratch?

again, please see the published literature. LAMMPS provides the tools,
the research you'll have to do yourself.