The keyword NIMET specifies a density based embedded atom
method (EAM4) for the chemisorption of hydrogen on a Ni(100) surface[57,58,59,60].
The structural model that can be used so far for the diffusion of H
on Ni(100) consists of a single hydrogen atom adsorbed on a
four-layered slab of 392 Ni atoms, with 98 atoms in each layer.
This number of Ni atoms was chosen so that the length of the
simulation box in the two lateral directions was more than twice
the cutoff distance of the EAM4 potential (10 Å). Periodic
boundary conditions are employed in the two dimensions
parallel to the surface, and the bottom layer of the lattice is