Hello,
I am using the LAMMPS version 29Oct2020. I am currently attempting to do a hybrid MD/MC simulation to calculate the diffusion coefficient of a LJ liquid using LAMMPS. I went through the documentation for ‘fix gcmc’ and there is a mention of the fluctuating number of atoms in the system while using this fix. I used the ‘compute_modify mdtemp dynamic/dof yes’ command to ensure that the number of atoms does not change with each timestep as per the documentation. But still, the number of atoms keeps increasing with each timestep. What could possibly be the reason for this happening? I am attaching my code along with this.
Regards,
Rajesh
SETTINGS
variable x equal 20
variable y equal 20
variable z equal 10
variable rho equal 0.6
variable t equal 1.0
variable rc equal 2.5
problem setup
units lj
dimension 3
atom_style atomic
neighbor 0.3 bin
neigh_modify delay 0 every 1 check yes
lattice custom ${rho} origin 0.0 0.0 0.0 orient x 1 0 0 orient y 0 1 0 orient z 0 0 1 &
basis 0.0 0.0 0.0 basis 0.5 0.5 0.5
region simbox block 0 $x 0 $y 0 $z
create_box 1 simbox
create_atoms 1 box
pair_style lj/cut ${rc}
pair_coeff * * 1 1
group mdatoms type 1
timestep 0.0001
dump 4 all atom 50000 LJ_Diff.lammpstrj
dump_modify 4 sort id
mass * 1.0
velocity all create $t 97287
compute mdtemp mdatoms temp
compute_modify mdtemp dynamic/dof yes
fix mdnvt mdatoms nvt temp 1.0 1.0 0.1
fix_modify mdnvt temp mdtemp
thermo 1000
unfix mdnvt
##---------------RELAXATION--------------------------------------
run 50000
##-------------------------MC STEP-------------------------------
fix 7 mdatoms gcmc 20 1000 1000 1 29494 1.0 0.0 0.01
timestep 0.0001
run 2000000