# LAMMPS input file (License CC BY 4.0)

# By Simon Gravelle, Jacob R. Gissinger, and Axel Kohlmeyer

# The DOI will be added upon publication

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

units real

atom_style full

bond_style harmonic

angle_style harmonic

dihedral_style harmonic

pair_style lj/cut/coul/long 10

kspace_style ewald 1e-5

special_bonds lj 0.0 0.0 0.5 coul 0.0 0.0 1.0 angle yes

region box block -30 30 -15 15 -15 15

create_box 8 box &

bond/types 7 &

angle/types 8 &

dihedral/types 4 &

extra/bond/per/atom 3 &

extra/angle/per/atom 6 &

extra/dihedral/per/atom 10 &

extra/special/per/atom 14

include parameters.inc

molecule h2omol water.mol

create_atoms 0 random 700 87910 NULL mol h2omol 454756 overlap 1.0 maxtry 50

group H2O type OW HW

minimize 1.0e-4 1.0e-6 100 1000

reset_timestep 0

fix mynpt all npt temp 300 300 100 iso 1 1 1000

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

shiny 0.1 box no 0.01 view 0 90 zoom 3 size 1000 500

dump_modify viz backcolor white &

acolor OW red acolor HW white &

adiam OW 3 adiam HW 1.5

variable myvol equal vol

variable myoxy equal count(H2O)/3

variable NA equal 6.022e23

variable Atom equal 1e-10

variable M equal 0.018015

variable rho equal ${myoxy}*${M}/(v_myvol*${NA}*${Atom}^3)

thermo 500

thermo_style custom step temp etotal v_myvol v_rho

timestep 1.0

run 15000

write_restart water.restart

# write_data water.data # uncomment to write a .data file as well