Fix rigid/minimize workaround

Hi All,

I realized after the fact, that the fix rigid does not work with minimize. Is there any workaround that won’t distort the bonds on the rigid particles?



In case it is of use to someone else, someone gave me a good answer to this question which uses “fix setforce”. It works when unoverlapping is the only objective …

To the rigid molecule(s) apply:

fix freeze RIGIDSTUFF setforce 0.0 0.0 0.0

  • other fixes

minimize …

unfix freeze

fix N RIGIDSTUFF rigid molecule

Getting the minimizers to work with constraints like
SHAKE or fix rigid is non-trivial. I don't know how
to do it correctly. So LAMMPS doesn't do it.