Fix GCMC Problem

Hi Lammps users,

I have to make a Fix GCMC simulation, in which I need to find out how many atoms are in a certain volume considering the pressure value in the input.
I have tried to start with a box that has already one molecule in it, but there is something wrong in my work and I cannot find out where the mistake is.

Input

units real
atom_style full
boundary p p p
pair_style lj/class2/coul/long 16.0
read_data argon_box_1.data
kspace_style ewald 1.0e-04
molecule 1 argon.txt
group Ar type 1
variable density equal atoms/vol
variable specdensity equal v_density/0.6022
fix 1 all gcmc 1 100 100 1 29494 87.0 1 0.05 mol argon.molecule pressure 0.4 fugacity 0.999 full_energy
thermo_style custom step temp pe press vol v_specdensity
run 4000
unfix gcmc

Sorry for the long delay in responding. The ERROR message seems pretty clear. fix gcmc can’t find the template ID that you specified. You should have said:

molecule argon.molecule argon.txt

Aidan