raphael,
please always copy the list on your replies.
Dear Dr Axel,
I tried to adjust the units setting all of them to "metal".
I continue "loosing" my atoms.
yes, because they are obviously very close to each other.
well, there is another issue: you don't seem to be aware
that the commands for region and create_atoms will use
the lattice grid vectors by default instead of angstroms.
in fact, there is no reason that you should even define
a lattice for your system. just remove the lattice keyword
and add "units box" to each, the "region" and the "create_atoms"
lines, and your input will do what you expect it to do.
cheers,
axel.