Hello everyone,
I hope you’re doing well. I have a question regarding fix gcmc. I found that I can’t perform MC moves (translation, rotation, etc.) when using fix rigid or fix shake. I want to know if there is any workaround for this. In my case, I’m working in saturated conditions, where I don’t expect any insertion or deletion, but I still need MC moves for sampling.
Is there any solution for this? thank you for your help 
One solution, which is probably not what you were hoping for, is to use a true Monte Carlo code instead of LAMMPS, like Raspa or GOMC.
Thank you for your reply
I was keeping this as my last hope 
. If I may ask you, which one of these (RASPA, Towhee, GOMC) is the easiest to export/import data from LAMMPS? I was considering doing a hybrid approach.
I am currently combining GOMC and LAMMPS to perform efficient hybrid MC/MD simulations, and I had to write Python converters to go from LAMMPS .data to .pdb/.psf files. Its not difficult, but its definitely annoying. I know people that are using Raspa and LAMMPS similarly, and they also had to write their own converters. There may not exist an easy solution currently, although I don’t know anything about Towhee so may be there are smarter solutions out there.
Thank you very much for your help. I just have one last question: does GOMC support defining regions like LAMMPS?
I am not aware of that possibility, but I could be wrong. These Monte Carlo codes typically have (much) fewer options than LAMMPS, unfortunately.
Please note that you could use LAMMPS just as a “force engine” and drive the simulation with an external code using the MDI package or through the LAMMPS script/library interface. There are several examples bundled with LAMMPS, including a simple “MC driver”.
Thank you very much for your help , 