[lammps-users] Need forces on clamped atoms

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1

Hi,
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?

Thanks

2

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

Steve

3

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

Steve