I am trying to simulate a mixture of CO2 and N2, but I keep getting ‘ERROR: Lost atoms’. I further increased the size of the box, performed minimization yet I am still getting the error. I understand there should be a rigidifying command, but I am finding it hard to implement it. Please Can anybody help. Below are my input script and data file. Thank you

units real

atom_style full

boundary p p p

read_data CO2_initial.data

pair_style lj/cut/coul/long 12

pair_modify tail yes

bond_style harmonic

angle_style harmonic

kspace_style pppm 1.0e-4

include PARM.lammps

molecule N2 N2.mol

create_atoms 0 random 5 428515 NULL mol N2 645341

group CO2 type 1 2

group n2 type 3 4

#neighbor 2.0 bin

#neigh_modify every 1 delay 0 check yes

#Minimization

thermo 10

min_style sd

minimize 1.0e-4 1.0e-6 1000 10000

variable dt equal 1

timestep ${dt}

reset_timestep 0

velocity all create 300 4932567 dist uniform

variable kinetic_energy equal ke

variable potential_energy equal pe

variable pressure equal press

variable Temperature equal temp

variable Density equal density

variable total_energy equal etotal

fix 1 all npt temp 300 300 100 iso 78.9539 78.9539 1000

thermo 1000

#fix myave1 all ave/time 10 100 1000 v_Temperature v_kinetic_energy v_potential_energy v_total_energy v_pressure file energy1.data

thermo_style custom step temp density epair ke etotal press vol

run 500000

DATA FILE

```
**N2**
# N2 molecule file. TraPPE model.
3 atoms
2 bonds
1 angles
Coords
1 0.0 0.00 0.00
2 -0.55 0.00 0.00
3 0.55 0.00 0.00
Types
1 3
2 4
3 4
Charges
1 0.964
2 -0.482
3 -0.482
Bonds
1 1 1 2
2 1 1 3
Angles
1 1 2 1 3
--------------------------------------------------------------------------
**PARM**
# Masses
mass 1 12.0107 #C
mass 2 15.9994 #O
mass 3 1e-20 #COM
mass 4 14.005 #N
# Pair coeff
pair_coeff 1 1 0.05365359 2.8000
pair_coeff 2 2 0.15698643 3.05000
pair_coeff 1 2 0.09177627989 2.9250
pair_coeff 4 4 0.07153812 3.31000
pair_coeff 1 4 0.06195382926 3.055
pair_coeff 2 4 0.1059741198 3.180
pair_coeff * 3 0.000000000000 0.000
# Bond coeff
bond_coeff 1 5000.00 1.16
bond_coeff 2 5000.00 0.55
# Angle coeff
angle_coeff 1 500.0 180.00
angle_coeff 2 500.0 180.00
```