I simulated with multisphere in the liggghts-PFM version, acquiring a portion of the specimen via the displace_atoms command and delete_atom command. Both commands work, but after continuing to run, the intercepted portion goes back to its original position. displace_atoms doesn't seem to work, why is that? Is the particle location not updated correctly?
region bc block 0 1 0 1 0 1 units box side out
displace_atoms all rotate 0 0 0 0 1 0 30
delete_atoms region bc