[lammps-users] lost atoms, nan , temperature shooting of the system

Hi lammps community i am trying to model LCO (lithium cobalt oxide )using Buckingham potential. i am using the following script

units metal
dimension 3
boundary p p p
atom_style atomic

lattice custom 1 a1 5.632 0 0 a2 0 4.920 a3 0 0 14.05 basis 0 0 0 basis 0.5 0 0 basis 0.25 0.5 0 basis 0.75 0.5 0 basis 0.25 0.1666 0.0833 basis 0.75 0.1666 0.0833 basis 0 0.666 0.0833 basis 0.5 0.666 0.0833 basis 0 0.333 0.1666 basis 0.5 0.333 0.1666 basis 0.25 0.833 0.1666 basis 0.75 0.8333 0.1666 basis 0 0 0.25 basis 0.5 0 0.25 basis 0.25 0.5 0.25 basis 0.75 0.5 0.25 basis 0.25 0.1666 0.3333 basis 0.75 0.1666 0.3333 basis 0 0.666 0.3333 basis 0.5 0.666 0.3333 basis 0 0.333 0.4166 basis 0.5 0.333 0.4166 basis 0.25 0.833 0.4166 basis 0.75 0.8333 0.4166 basis 0 0 0.5 basis 0.5 0 0.5 basis 0.25 0.5 0.5 basis 0.75 0.5 0.5 basis 0.25 0.1666 0.5833 basis 0.75 0.1666 0.5833 basis 0 0.666 0.5833 basis 0.5 0.666 0.5833 basis 0 0.333 0.6666 basis 0.5 0.333 0.6666 basis 0.25 0.833 0.6666 basis 0.75 0.8333 0.6666 basis 0 0 0.75 basis 0.5 0 0.75 basis 0.25 0.5 0.75 basis 0.75 0.5 0.75 basis 0.25 0.1666 0.8333 basis 0.75 0.1666 0.8333 basis 0 0.666 0.8333 basis 0.5 0.666 0.8333 basis 0 0.333 0.9166 basis 0.5 0.333 0.9166 basis 0.25 0.833 0.9166 basis 0.75 0.8333 0.9166
region box block 0 10 0 7 0 3
create_box 3 box
create_atoms 1 region box &
basis 5 3 &
basis 6 3 &
basis 7 3 &
basis 8 3 &
basis 13 3 &
basis 14 3 &
basis 15 3 &
basis 16 3 &
basis 21 3 &
basis 22 3 &
basis 23 3 &
basis 24 3 &
basis 29 3 &
basis 30 3 &
basis 31 3 &
basis 32 3 &
basis 37 3 &
basis 38 3 &
basis 39 3 &
basis 40 3 &
basis 45 3 &
basis 46 3 &
basis 47 3 &
basis 48 3 &
basis 9 2 &
basis 10 2 &
basis 11 2 &
basis 12 2 &
basis 25 2 &
basis 26 2 &
basis 27 2 &
basis 28 2 &
basis 41 2 &
basis 42 2 &
basis 43 2 &
basis 44 2 &

#Li
mass 1 6.941
#Co
mass 2 58.93
#O
mass 3 15.99

#set type 1 charge 1
#set type 2 charge 3
#set type 3 charge -2

pair_style meam
pair_coeff * * library.meam Li Co O library.meam_alloy Li Co O
#pair_style buck/coul/long 12
#pair_coeff 1 1 1764 4.89 4.6999
#pair_coeff 2 2 978.9 4.1783 6.8127
#pair_coeff 3 3 25276 4.024 83.309
#pair_coeff 1 2 1270.2 4.5232 5.4423
#pair_coeff 1 3 9246.5 4.5835 19.304
#pair_coeff 2 3 2046.4 3.7855 25.5176

#kspace_style ewald 1.0e-4

neigh_modify every 2 delay 10 check yes page 100000

timestep 0.001

#thermo 10
#thermo_style custom step lx ly lz temp ke pe

#dump 1 all atom 10 lco1.lammpstrj

#min_style cg
#minimize 1.0e-50 1e-6 10000 100000

#velocity all create 300 123542
fix 1 all npt temp 300 300 0.001 iso 1 1 0.01
#fix 2 all nvt temp 300 300 0.01
thermo 10
thermo_style custom step lx ly lz temp ke pe
dump 4 all atom 10 lco.lammpstrj

run 10000
print “done”

i want to stabilize my system but when i run it the system just get blast and i am getting nan values
i rechecked
the Buckingham pair_coeff parameters which i got from this source
https://linkinghub.elsevier.com/retrieve/pii/S0167273815002635

and
https://pubs.acs.org/doi/abs/10.1021/ja00051a040

check the units which is correct

recheck the structure
tried different timestep and damping factors but nothing change

can anyone just give me any hint and reference to previous archives on similar issue to solve it.

thanks in advance

This input is not using buckingham but MEAM.
If the system is behaving badly, that either means you have a bad geometry (e.g. overlapping atoms, either directly or via periodic images) or bad potential settings or parameters.

axel.