Dear LAMMPS developers and users,
I have observed a strange behavior of the optimized EAM routine (pair_style
eam/opt). What I can say is that at least for one simple test case it gives
different energies than the standard EAM routine (pair_style eam).
With this email I have included a small LAMMPS script that calculates the bond
energy of a Pd dimer as a function of bond length. With the eam/opt pair
style it gives a wrong energy curve with a very deep second well at small
atomic distances. If you change the pair style to "eam" it gives you the
I haven't found out myself what the problem is yet or where to find the bug in
the eam/opt code. I hope that the developers of the eam/opt routine know it
better. What I can say is that the error arises only with certain potential
Maybe someone can verify my observations.
dimer.in (876 Bytes)
eam.Pd.Pd.LAMMPS.Foiles (35.6 KB)