Dear lammps users, currently I’m working on the equilibrium of the composite, consisting of clay(rigid body), and polymer(non-rigid). Now, I have a problem with performing time integration for both rigid & non-rigid parts. After a lot of searching, I decided to just use fix rigid for rigid bodies and use time integration ones for the non-rigid parts. it means that I do not want to use time integration for a rigid part. Is it Ok?
This sounds like you are confusing “immobilizing” with keeping “rigid” (as quite a few people do for some mysterious reason).
If you don’t want the clay atoms to move, define a group for all other atoms (e.g. via a range of atom types or range of atom IDs) and apply time integration (fix nve/nvt etc.) only to them.
Fix rigid moves one or more sets of atoms as a rigid body. Do you have such particles in your system? That would require one of the fix rigid time integrator variants.
Yeah, I wanted to immobilize the clay. Thanks for your reply.