[lammps-users] fix_addforce

Steve,

I am applying force on a group of atoms using fix addforce and i want to see the contribution of this force to the potential energy of the system. I actually want to distinguish the two potential energies, the one because of interatomic potential and the other due to added force. Is there any way to do that?? I thought of using fix_modify command but it isn’t working. I am attaching the part of the code. Please let me know where i was wrong.

If I add these commands to bench/in.lj

fix 5 all addforce 0.0 0.0 1.0
  fix_modify 5 energy yes
  thermo_style custom temp pe ke etotal press f_5

then I get output. Are you using the most current version
of LAMMPS?

Steve