fix nvt + gcmc lost atom and system is not charge neutral

And before that, I have
gotten the density of methane using GCMC in LAMMPS successfully. However, I
don't understand how the hybrid NVT+GCMC simulation perform, and why the NVT
simulation is necessary. Always, the temperature of methane(adsorbate) in my
out file is extremely low. I think the low temperature is unreasonable,
because my eventual purpose is to get the adsorption isotherm in 300K, not
1K or other low temperature. So, would you like to give me more suggestions
about the adsorption simulation in LAMMPS? And how can I control the
temperature of adsorbate to my expection.

As Jacob Gissinger pointed out in a previous post to the mailing list,
using fix nve/limit may improve the numerical stability of simulations
that use fix gcmc. (But you will also have to include a separate fix
which regulates temperature like "fix langevin", because "fix
nve/limit" is not a thermostat.)

              I am truely thankful for your help, it is valuable for my
research. Before performing my GCMC, I have already check my data file
seriously and I am sure it is electrical neutrality.

If LAMMPS is printing "System is not charge neutral", this means that
when LAMMPS calculated the sum of the charges in your system, the
result was not zero. (See line 296 of "kspace.cpp" in the LAMMPS
source code.)

I do not know if this is the reason for your problem. But I think it
is a serious problem.

If you have a DATA file, you can calculate the sum of the charges by
entering these two commands into the terminal: