ERROR: Lost atoms: original 8000 current 7996 (../thermo.cpp:389)

Hello everyone,

I am Upamanyu and am getting an error while carrying out a basic equilibration simulation of SiC. I am trying to use the SiC.Tersoff potential file.

The error is : " ERROR: Lost atoms: original 8000 current 7996 (…/thermo.cpp:389) " and is happening after completion of the NPT and NVT ensembles (after 10 ns). This happens due to bad dynamics but I am failing to understand where exactly I am making a mistake.

I have tried changing the damping time and the minimisation parameters but of to no avail. Can anyone please help me with their expert advice on where exactly I am going wrong?

Thank you so much for your time.

Yours sincerely,

Regards,
Upamanyu

INPUT SCRIPT

dimension 3
units metal
atom_style atomic
read_data data.SiC

mass 1 28.0855
mass 2 14.0067

pair_style tersoff
pair_coeff * * SiC.tersoff Si C

#replicate 10 10 10

dump 2 all custom 100 SiC.lammpstrj id type x y z

thermo 1
thermo_style custom step temp epair etotal press vol
minimize 1 10 100 10000

velocity all create 300.0 4928459

fix 1 all npt temp 300.0 300.0 0.1 iso 0.0 0.0 1000
thermo 200
timestep 0.001
run 5000000
unfix 1

fix 2 all nvt temp 300.0 300.0 100
thermo 200
timestep 0.001
run 5000000
unfix 2

write_restart equil.restart1

fix 3 all nve
run 2000000
unfix 3

Regards,
Upamanyu

Hello everyone,

I am Upamanyu and am getting an error while carrying out a basic
equilibration simulation of SiC. I am trying to use the SiC.Tersoff potential
file.

The error is : " *ERROR: Lost atoms: original 8000 current 7996
(../thermo.cpp:389)* " and is happening after completion of the NPT and
NVT ensembles (after 10 ns). This happens due to bad dynamics but I am
failing to understand where exactly I am making a mistake.

I have tried changing the damping time and the minimisation parameters but
of to no avail. Can anyone please help me with their expert advice on where
exactly I am going wrong?

​how is your energy conservation during the NVE part of the run?

...and please *always* state which version of LAMMPS are you using.

axel.

You might want to minimize your structure first. You minimize command is
not minimization.

Ray