Molecule attributes do not match system attributes (happens when using gcmc)

Hello everyone,
I am using fix gcmc to add water to CNT. First I use NVT to equilibrate the water already inside CNT. Then I use NVT withc GCMC to add water.
There is a warning, Molecule attributes do not match system attributes (…/molecule.cpp:1386). This warning does not happen when I equilibrate in the very beginning.
I checked my molecule file and found nothing wrong. And my simulation will be stuck in the middle…
However, if I set M in the gcmc command to be 0 (no MC moves), the simulation can run to the end. But the warning is still there.
So what is wrong here?
Thanks.

My gcmc commmand is these two commands.

fix 1 water nvt temp {T} {T} {Tdampn_r} fix addwater water gcmc 1000 1 1000 0 {ransed} ${T} -5.8 1.0 mol one_water region rmc full_energy

Here is my force field settings.

#----------Force field parameters----------

#CNT C=1
#H2O H=2, O=3

pair_style lj/cut/coul/long 12.0 11.0
pair_modify mix arithmetic
bond_style harmonic
angle_style harmonic
kspace_style pppm 1.0e-4

#CNT
#These Lennard-Jones parameters come from
#R. Saito, R. Matsuo, T. Kimura, G. Dresselhaus, M.S. Dresselhaus, Chem Phys Lett, 348:187 (2001)
pair_coeff 1 1 0.068443 3.407 #C-C

#TIP3P water H=2,O=3
pair_coeff 2 2 0.0 0.0 #H-H
pair_coeff 3 3 0.102 3.188 #O-O
pair_coeff 2 3 0.0 0.0 #O-H
bond_coeff 1 450 0.9572 #H-O
angle_coeff 1 55 104.52 #H-O-H

#CNT-H2O
#Specify (C-O interactions). DOI: 10.1021/nl1021046, Nano Lett. 2010, 10, 4067–4073 and
#See Laurent Joly, J. Chem. Phys. 135(21):214705 (2011) for details
pair_coeff 1 2 0.0 0.0 #C-H
pair_coeff 1 3 0.114 3.28 #C-O

The following is my water molecule file.

3 atoms
2 bonds
1 angles

Coords

1 1.550000 1.550000 11.500000
2 1.550000 2.306950 12.085880
3 1.550000 0.793050 12.085880

Types

1 3
2 2
3 2

Charges

1 -0.830
2 0.415
3 0.415

Masses

1 15.9994
2 1.008
3 1.008

Bonds

1 1 1 2
2 1 1 3

Angles

1 1 2 1 3

i cannot say for certain, since you didn’t provide your complete input, but the warning is likely due to the fact that you define “Masses” in your molecule file for an atom style where the masses are tied to atom types and thus do not need to be specified in the molecule file. this is likely not the reason for the stalling though.

axel.