[fix ttm/mod] problem about unchanged temperature of atoms

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1

hello,everyone

i m trying to use ‘fix ttm/mod’ to study the laser ablation of Au foil and i met some problem in the simulation process.

when i use ‘fix ttm/mod’ , the laser energy was deposited in the electron system and the electron temperature raised up to 8000+K, however, the temperature of the atoms was keeping unchanged during the process with 300K. im sure that i set the electron-phonon coupling term ‘gamma_p’ to provide the langevin force for the atom system in the parameter profile. so why did atomic system not being affected ?

something i need to mention that:

  1. i did not consider the effect of the electron pressure and electron stopping, so i set the parameter ‘gamma_s’ and ‘B’ to be zero. is this setup lead to the difference?
  2. i just use the only fix command ‘fix ttm/mod’ in the input file. to update the atomic configuration, should i set one more fix like ‘fix nve’ or something?

thanks in advance.

2

if you do not time integrate the atom positions, there cannot be a change in their kinetic energy and thus their temperature.

axel.