[lammps-users] Units conversion problem

I'm not 100% clear on your question, but this
is what other LAMMPS pair styles do that read params
from a file. They tell the user in the doc page that
the provided file(s) in the potentials dir are in a
certain unit system, e.g. metal for EAM potential files.
This means that any value in the file is the appropriate
metal units, e.g. eV for energy. Then the doc
page says that if you want to run a LAMMPS model
in another unit system, e.g. "real" or "si" units,
it is up to the user to create a potential file
that lists its values in those units.