Lost atom error during optimisation

Dear lammps users,

I am optimising randomly generated structures of nanocluster of (ZnO)5 with the COMB3 potential.

However, COMB3 gives the “lost atom error” about 5 % of chance even though the .xyz file contains all of atoms, which is 10 atoms.

ERROR: Lost atoms: original 10 current 9 (…/thermo.cpp:438)

What is this error means? I presume there is another kind of error during the optimisation?

I appreciate any advices and insights.

Here is the log file:

Dear lammps users,

I am optimising randomly generated structures of nanocluster of (ZnO)5 with the COMB3 potential.

However, COMB3 gives the “lost atom error” about 5 % of chance even though the .xyz file contains all of atoms, which is 10 atoms.

ERROR: Lost atoms: original 10 current 9 (…/thermo.cpp:438)

What is this error means? I presume there is another kind of error during the optimisation?

you are running with “fixed”, i.e. non moving, non-periodic bounadries. are you sure this is what you intend?

if an atom moves outside your box it is being discarded or “lost”.
if you want the box to be extended when an atom moves outside that boundary, you can use “m” boundaries, instead.

axel.