GCMC with molecules

Dear all,

I have changed the CGMC LAMMPS code to enable GCMC with molecules.
Charges are enabled and the version works for any molecules.
The new fix_gcmc.cpp file is attached
The reservoir is not infinite now and data file should contain the
molecules of reservoir, wich do not interact.
If number of molecules is not enough error message occurs.

fix ID group-ID gcmc N X M type seed T mu displace keyword values
keyword = molecule
molecules = Ntm, where Ntm is the number of atom types in molecule

data file
Data files should be changed this way
It should contain Nt+2*Ntm atom types, where Nt - number of atom types
in original date file
Pair coefficients of Nt+1 - Nt+Ntm are pair coefficient of atoms in molecules,
Pair coefficients of Nt+Ntm+1 - Nt+2*Ntm are zeros, meaning no interaction
Charges of atoms of molecules in reservoir are charges of atoms in
molecules devided by 10^10 meaning no interaction (may be set by " set
type __ charge __" command)
Each molecules should have its own molecule number (may be set by "
set atom __ mol__ " command).
Atoms of molecules of reservoir may be inserted to datafile by
create_atoms command, angles and bonds inside molecules were manually
inserted into datafile using e.g. excel.
I did not need MC displacement for molecules and this function is not
implemented, use M=0, and I did not need parallelization, but this
features may be enabled.
Would you have more question please contact me.

[email protected],
Byshkin Maxim
department of Chimestry
University of Salerno, It

fix_gcmc.cpp (20.3 KB)

fix_gcmc.h (3.16 KB)

thanks - this looks interesting.

Paul is the one who works with GCMC, so he can take
a look at your files ...


Yes, this is interesting. I've likewise been working on a molecule capability for LAMMPS's GCMC. From your description, it sounds like there are some important differences. Let's coordinate off-list. If others would like to help beta test the molecule capability for fix GCMC, please let us know.