I’m a complete newcomer at MD simulations, so I apologize when my question is a bit stupid. I’m trying to simulate a laser welding process of metal. I wanted to incorporate the MEAM and TTM methods. Unfortunately, there’s no phonon-electron coupling term in the LAMPPS TTM model. I found the fix atc command. Will it be possible to use this one to simulate a continuous phonon irradiation of the metal atoms, or can it only simulate an irradiatation of specified FM cells?
Thank you for your answer in advance. Best Regards,
There is electron phonon coupling.
The coefficient gamma_p in “fix ttm” corresponds to electron-phonon coupling.
As I understand, authors called it electron-ion interactions because it’s some generalization to cases
like melting, cascades … But if kinetic energy of atoms is small enough to keep atoms close to equilibrium
positions, it’s electron-phonon interactions.
There are to my knowledge two TTM models in LAMMPS: one through the ‘fix ttm’ that was mentioned and the other through ATC. They each have different feature sets so you should think about the problem that you would like to run and see which would be most appropriate. If you would like to use ATC, there are several ATC developers who monitor the lammps-user list and we can provide suggestions. In terms of your question, I’m not sure I fully understand what you’re asking, but ATC does allow energy to be input into either the phonon or electron temperature separately per the user’s specifications.