Problem with fix/ttm

dear users,

I am trying to include some electron analysis in metallic materials like silver and copper. I am slightly confused regarding the methodology of doing it.
Can we use fix/ttm along with fix/NVE to include the electron effects in a finite size domain (few nanometers of size) ?


Fix TTM has to do with the temperature of electrons. I suggest
you read the papers cited by its doc page. If you want some
other arbitrary effect due to electrons, then the answer to your Q is no.



Are there any example programs available for “fix/ttm” command on any material? I couldn’t find any in the EXAMPLES folder.
I tried to run some on my own. But they were terminated with “segmentation fault” message. If anyone has used “fix/ttm” command for any purpose please let me know.


Paul probably has some example scripts.


Yes, here's an example script (please see attached).

Paul (957 Bytes)

initialTs (146 Bytes)


I want to make sure the units of rho_e in fix/ttm is no. of electrons/Ang^3 in “metal” units. Since in the units command, its been mentioned that units of density are “grams/cm^3”, i am little confused.


Paul will have to answer this. The doc page says electrons/volume, so
that should be # per Angs^3 in metal units. Density is something else,
used by some other commands. If that's what fix ttm wanted, the
doc page should say density units.


Yes, the docs say:

"rho_e = electronic density (electrons/volume units)"

So it should be number of electrons per angs^3 if you're using metal units.