The keyword NIHEAM7 specifies an embedded atom
method (EAM7) for the chemisorption of hydrogen on a Ni(100) or Ni(111) or Ni(110)
The structural model is as in NIMET (EAM4). The functional forms combine
EAM4,[59,60] EAM5, EAM6, and EAM7.
Be aware that the parameters were to crudly approximated and some functions had typos in the
original EAM6 paper so they have been taken from the original f77 code and this paper .
The gradient correction for the hydrogen embedding function in EAM6 is neglected at the moment,
since the original code doesn't include it as well.