Thermal Conductivity of silicon

Dear Users,

I am running the Langevin method (explained in KAPPA example) for Silicon thermal conductivity. I have attached the input file, log file and the temperature profile. I have read the explanation in the README file for the KAPPA example, but I could not find the right thermal conductivity. I have two main questions (I am new with LAMMPS, I would appreciate if you could explain in a simple way) :

1- for calculating Q what parameters should I use? I mean what are the heat fluxes?

2- which temperature I should use for calculating the delta T.

Thank you in advance for your help.


log.lammps (12.9 KB)

profile.langevin (93.6 KB) (2 KB)

Si.sw (652 Bytes)

When the fundamental knowledge is absent, examples can quickly become troublesome as one struggles trying to get results in a trial and error fashion while not understanding their inner workings. You should put aside for a bit your lammps numerical attempts and grab a/some book/papers where the theory is discussed and sit and do some reading.

Only the right attitude leads you to becoming more self-sufficient and independent. How to proceed is totally up to you, but I doubt you’ll get your answers following your current approach. And no, your problems are not because you are a beginner to lammps…


The examples in KAPPA are just to demonstrate the
methods. Devising a simulation that is valid for
a specific material is up to you - it’s not really
a LAMMPS question. A good first step is to reproduce
some calculation in the literature.