LAMMPS in. file

clear

units           metal
atom_style      charge
boundary        p p s

read_data       data.SiO2_offset_1.20_0.45 # generated automatically, -1 charge on O, -2 on Si

variable e equal pe
variable et equal etotal

dump myDump all custom 1 dump.SiO2_offset_1.20_0.45 id mass x y z q

#define atomic masses
mass            1 28.086 # atom label 1 = SiO2 silicon
group           type1 type 1
compute         charge1 type1 property/atom q # computes the charge
compute         q1 type1 reduce ave c_charge1 # q1 = average(charge1) for all charge1 ats
mass            2 16.00 # atom label 2 = oxygen
group           type2 type 2
compute         charge2 type2 property/atom q # computes the charge
compute         q2 type2 reduce ave c_charge2 # q2 = average(charge2) for all charge1 ats

pair_style      comb # comb 10, Sinnot et al.
pair_coeff      * * ../potentials/ffield.comb Si O # Si & O are treated with COMB
neighbor        2.0 bin
neigh_modify    every 20 delay 0 check no

timestep        0.001


thermo_style    custom step etotal vol

fix             1 all nve
fix             2 all qeq/comb 1 0.0005

run 1

#fix        freeze all setforce 0.0 0.0 0.0

print "Initial potential energy = $e"

min_style   cg
minimize        1.0e-20 1.0e-30 200 10000

print "Final potential energy = $e"
print "Final total energy = $et"
print "  !!!!  FINISHED  !!!!  "