[lammps-users] Fix the location of the atoms

Dear lammps-folks,

I have a similar question to the one posted here (see below). I would need to fix some atoms in the unit cell so they do not move, but I would like to have (dump) the forces acting on them... I guess if I do not include the atoms in the fix command the forces won't be calculated???
Am I right??

thanks
Alex

Steve Plimpton <[email protected]> - 2009-04-16 14:05

If you don't integrate those atoms they won't move. If you
do, and set the force to 0.0, the velocity also needs to be
zero, or they will move.

Steve

> Dear Lammps Users,
>
> I am trying to fix the certain group of the atoms during the simulation.
>
> I used the fix setforce command to zero the atoms, but it seems to me not working
properly.

Use fix nve (or whatever) on just the
atoms you want to move. Dump forces on
all atoms. The other atoms won't move and
you'll get forces on all atoms.

Steve