LAMMPS error

Hi everyone,
recently in an md simulation, I got the error “Out of range atoms- cannot compute PPPM(src/KSPACE/ppm.ccp;1887)”.The answer for this is that the box size is large and a small cluster of molecules. Plz suggest how to fix this,thanks in advance.

I suggest you read the abundant advice given over decades on this very error. The forum should have already suggested relevant posts even before you posted this message, isn’t it?

Basically it means your simulation exploded and atoms moved too far in a single time step. May have bad force field parameters, or have overlapping atoms and need to relax the system. As @hothello mentioned, there are many posts on the topic already, so searching will provide more info.