Using fix spring/self with rigid bodies

Dear LAMMPS Developers,

Can I apply fix spring/self to atoms belonging to rigid bodies? I noticed in the lammps manual that fix spring “should not be used with the fix spring command, if the rigid body will cross a periodic boundary”. However, there is no limitation indicated in the manual for fix spring/self, and there is a sentence saying “The distance r correctly takes into account any crossings of periodic boundary by the atom since it was in its intitial position.” for fix spring/self. So I’m assuming that fix spring/self can be applied to atoms belonging to rigid bodies. Am I right? I appreciate your help!

Thanks,
Jibao

Dear LAMMPS Developers,

Can I apply fix spring/self to atoms belonging to rigid bodies? I noticed in
the lammps manual that fix spring "should not be used with the fix spring
command, if the rigid body will cross a periodic boundary". However, there

i think that limitation no longer applies. fix rigid used to modify
the image flags which are crucial for computing the center of mass for
the fix spring group (which is based on unwrapped coordinates), but
that is no longer the case and thus fix spring should work with fix
rigid when using a recent version of LAMMPS.

is no limitation indicated in the manual for fix spring/self, and there is a
sentence saying "The distance r correctly takes into account any crossings
of periodic boundary by the atom since it was in its intitial position." for
fix spring/self. So I'm assuming that fix spring/self can be applied to
atoms belonging to rigid bodies. Am I right? I appreciate your help!

the limitations to fix spring/self with respect to image flags are the
same as for fix spring. for old LAMMPS versions, where image flags are
modified for atoms in rigid objects, the unwrapping operation may give
incorrect results with fix spring/self. however this should also not
apply to recent versions of LAMMPS.

axel.

Dear Axel,

Thank you for your answer. I appreciate your help!

Jibao

I removed that warning about rigid bodies from the fix spring doc page.

Steve