[lammps-users] potential

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1

Dear LAAMPS,

Is there any guru to explain the eam potential format?

1. Nrho drho --> where are these used?
I think drho is d(sum of rho). Am I correct?

2. What is electron density in the potential file ?
I think electron density in potentail file is rho(r) (not sum of rho(r))

3.Is there a specific unit of electron density I should use?
where is this electron density used in LAMMPS?
I think unit of electron density doesn't matter if this return F(rho), eV
e.g.) eV/A^3 or eV/A^2 will not matter if those make F(rho) unit of eV
Am I correct?

Thank you for your time.

Sincerely,
Jay

2

First, be sure to read this doc file carefully, as it explains
everything:

http://lammps.sandia.gov/doc/pair_eam.html

Nrho is the # of tabulated values for the F() function in
the file. Just like Nr is the # for the functions that are a function
of r. Drho is the "spacing" in rho just like dr is the spacing in r.

Units are discussed on the doc page. Electron density is
not clear (for existing EAM files), but it doesn't really matter
so long as rho() produces density and F(rho) produces eV.

Steve