gcmc usage

Dear all,

hi, the lammps users .I want to ask you a question about gcmc command.

fix ID group-ID gcmc N X M type seed T mu displace keyword values ...

I want to use the fix gcmc command in source region to keep the solute’s concentration constant in the region, the fix gcmc command 's group ID is the solute’s group ID, or source’s groupID.

With regards!

your question makes little sense. the source is not part of the simulation, but just a virtual (infinite) reservoir, so there cannot be a group there.
also, in LAMMPS a fix operates (only) on the atoms in the fix group unless the documentation says the fix group is ignored. and the fix gcmc documentation clearly states that inserted atoms are added to the fix group (and any additional groups listed as optional keywords).


Using the terminology of your question, the group-id should be set to the solute group, while the optional region keyword should be set to the source region. Both of these LAMMPS objects (solute group and source region) must be defined before the fix gcmc command.

thanks very much!