Lammps

Hello everyone, I have some problems in the process of using lammps for coal pyrolysis, I hope you can give advice. I modeled the unit cell in MS as 13 monomolecules, each with a molecular weight of C143H116O33N2S, but I found that my product was C1714H423O13N13S1053 during the pyrolysis process, and I didn’t understand why.My in file and data file are as follows

LAMMPS data file written by OVITO Basic 3.10.6

3549 atoms
5 atom types

0.0 34.7638 xlo xhi
0.0 34.7638 ylo yhi
0.0 34.7638 zlo zhi

Masses

1 12.0107 # C
2 15.9994 # O
3 14.0067 # N
4 32.065 # S
5 1.00794 # H

Atoms # full

1 1 1 0.0 31.053111988 8.718065764 24.55541013
2 1 1 0.0 30.28796075 9.86422825 24.89609537
3 1 1 0.0 31.960794806 8.201128058 25.453011446
4 1 1 0.0 30.524702228 10.602611362 26.083974416
5 1 1 0.0 32.498590792 9.05423171 26.417706896
6 1 1 0.0 31.753602558 10.2727029 26.76464962
7 1 1 0.0 20.231836324 14.8093788 17.909614484
8 1 1 0.0 20.791533504 14.79721147 16.648036182
9 1 1 0.0 18.868747726 14.777743742 18.104291764
10 1 1 0.0 20.013172022 14.759666566 15.517517406
11 1 1 0.0 17.958631442 14.842056772 16.986635594
12 1 1 0.0 18.577427082 14.963034796 15.660744262
13 1 1 0.0 18.3031407 14.795125642 19.3808185
14 1 1 0.0 17.852254214 15.864807768 21.606744614
15 1 1 0.0 18.475569148 15.931901902 20.318745824
16 1 1 0.0 17.173664838 14.660937374 21.980803102
17 1 1 0.0 17.059639574 13.537718996 21.09467384

REAX potential for DJM system

units real

atom_style full
read_data DMJ.data

pair_style reaxff NULL
pair_coeff * * ffield.reax C H O N S

compute reax all pair reaxff
variable eb equal c_reax[1]
variable eqeq equal c_reax[14]

fix reax_qeq all qeq/reax 50 0.0 10.0 1e-6 reaxff
fix reax_out_species all reaxff/species 100 50 5000 DMJ.species.out element C H O N S cutoff 1 1 0.55 cutoff 1 2 0.4 cutoff 1 3 0.4 cutoff 1 4 0.4 cutoff 1 5 0.4 cutoff 2 2 0.55 cutoff 2 3 0.4 cutoff 2 4 0.4 cutoff 2 5 0.4 cutoff 3 3 0.55 cutoff 3 4 0.55 cutoff 3 5 0.55 cutoff 4 4 0.55 cutoff 4 5 0.4

fix reax_out_bonds all reaxff/bonds 5000 DMJ.bonds.out

neighbor 2 bin
neigh_modify every 500 delay 0 check no

thermo 5000
thermo_style custom step temp etotal v_eb v_eqeq spcpu cpuremain
dump traj all atom 10000 DMJ.lammpstrj
log DMJ.log

fix ensemble all nve
fix vrescale all temp/rescale 10 2500.0 2500.0 1.1 1.0

minimize 1e-4 1e-6 1000 1000
timestep 0.2

run 3000000

Please understand that the purpose of this forum is not to help you understand your research (that is the job of your adviser, supervisor, or tutor), but help overcome with problems in using the LAMMPS software itself. Not getting the expected simulation results is not a LAMMPS problem, unless you can provide proof that LAMMPS is not computing correctly.

p.s.: if you want help, you should use a descriptive subject line.