# LAMMPS Input File

# Licensed under CC BY 4.0

# A Set of Tutorials for the LAMMPS Simulation Package (LiveCoMS, 2025)

# By Simon Gravelle, Cecilia M. S. Alvares, Jacob R. Gissinger, and Axel Kohlmeyer

# Please cite doi.org/10.33011/livecoms.6.1.3037

# Find more on GitHub: https://github.com/lammpstutorials

units metal

boundary p p p

atom_style full

pair_style lj/cut/tip4p/long OW HW OW-HW HW-OW-HW 0.1546 10

kspace_style pppm/tip4p 1.0e-5

bond_style harmonic

angle_style harmonic

read_data cracking-mod.data

molecule h2omol H2O.mol

create_atoms 0 random 3 3245 NULL mol h2omol 4585 overlap 2.0 maxtry 50

group SiO type Si O

group H2O type OW HW

pair_coeff * * 0 0

pair_coeff Si OW 0.0057 4.42

pair_coeff O OW 0.0043 3.12

pair_coeff OW OW 0.008 3.1589

pair_coeff HW HW 0.0 0.0

bond_coeff OW-HW 0 0.9572

angle_coeff HW-OW-HW 0 104.52

variable oxygen atom type==label2type(atom,OW)

group oxygen dynamic all var oxygen

variable nO equal count(oxygen)

fix shak H2O shake 1.0e-5 200 0 b OW-HW a HW-OW-HW mol h2omol

dump viz all image 250 myimage-*.ppm type type &

shiny 0.1 box no 0.01 view 180 90 zoom 3.8 size 1700 700

dump_modify viz backcolor white &

acolor Si yellow adiam Si 2.5 &

acolor O red adiam O 2 &

acolor OW cyan adiam OW 2 &

acolor HW white adiam HW 1

compute ctH2O H2O temp

compute_modify thermo_temp dynamic/dof yes

compute_modify ctH2O dynamic/dof yes

fix mynvt H2O nvt temp 300 300 0.1

fix_modify mynvt temp ctH2O

timestep 0.001

variable tfac equal 5.0/3.0

fix fgcmc H2O gcmc 100 100 0 0 65899 300 -0.5 0.1 &

mol h2omol tfac_insert ${tfac} shake shak full_energy pressure 100

thermo 250

thermo_style custom step temp etotal v_nO &

f_fgcmc[3] f_fgcmc[4] f_fgcmc[5] f_fgcmc[6]

run 25000