Question about fix ttm

[RajeshR]

Hello everyone,

I am trying to calculate the thermal conductivity of an Inconel (Ni-Cr-Fe)/Cu multimetallic composite with an interface. I read that in order to get the electronic as well as the phononic contributions to the thermal conductivity, I have to use the two-temperature model, implemented using fix ttm in LAMMPS. Since thermal conductivity is an input parameter used by fix ttm, do I make a calculated guess for the thermal conductivity value that I use in fix ttm? And since I am calculating the thermal conductivity of my material, is there any other way to do this that does not involve having to specify a thermal conductivity as an initialized parameter? Thank you in advance.

Regards,
Rajesh

[akohlmey]

@RajeshR

I read that in order to get the electronic as well as the phononic contributions to the thermal conductivity, I have to use the two-temperature model, implemented using fix ttm in LAMMPS.

That must be some misinterpretation of what you read. As the documentation for fix ttm says, it represents the heat transfer through and between electronic and atomic subsystems. For that it requires the thermal conductivity of the electronic system as input. You cannot determine something when the very same property is an input parameters. LAMMPS can only determine the ballistic contributions to thermal conductivity.