[lammps-users] Need forces on clamped atoms

I’m running an indentation simulation. The atoms on the edges are fixed using:

fix boundaryatoms setforce 0.0 0.0 0.0

This allows my simulation to run well, but at some point I would like to calculate the forces on this edges. I know this could be done by running a single-energy calculation on my last frame, but I was wondering if there was another way to fix those atoms, without imposing a zero-force. Like simply not considering them during the calculations.

Is there some fix command to do that? And has anyone encountered the same issue and found a way to deal with it?


Don't integrate them (fix nve, fix nvt, etc) and
they won't move.


Fix setforce also allows you to access the force
on the atoms before they were reset. See the doc page.