gcmc Lost atoms running on multi nodes

Dear lammps-users,

I am using gcmc package in lammps to simulate gas adsorption in porous materials, and I test the input in.gcmc.lj in examples on multi nodes(10 nodes and 240 cpus), but I got error lost atoms. In addition, I found it can be done on 2 nodes 48 cpus. So, is it fix GCMC having problems running on multi nodes? Is there any way to solve this problem? The lammps version I used was 3Mar2020. Thanks for your help.

Best regard

Dongbo Wang

the example input has a system with less than 100 atoms.

it is complete pointless to run such a tiny system on thousands of CPUs. when you run LAMMPS with too many MPI ranks it will lose atoms without special precautions. the domain decomposition and default simulation parameter settings assume that people will run LAMMPS only with a number of MPI ranks that is reasonable for the given system.
as you can see from the provided log files in LAMMPS even when running in parallel with only 4 MPI ranks there is only a minimal speedup.