Dear all,

I’m confused by the description of the pair_eam document and the source code to generate eam potential in the tools/eam_generate in lammps source tree.

The pair_eam document here said:

Unlike the effective charge array Z® in

funcflfiles, the tabulated values for each phi function are listed insetflfiles directly as r*phi (in units of eV-Angstroms), since they are for atom pairs.

For me, my comprehension is that the phi function listed in setfl is the value of r*phi.

However, the source code of Cu_Mishin1.eam in the tools folder shows this:

double V (double r) {

return ( E1M(r,r01,a1) + E2M(r,r02,a2) + d ) * psi ( (r-rc)/h ) -

H (rs1-r)S1pow(rs1-r, 4.) -

H (rs2-r)S2pow(rs2-r, 4.) -

H (rs3-r)S3pow(rs3-r, 4.);

}// Pair potential

for (i = 0; i < Nr; i++)

fprintf (LAMMPSFile, “%20.20f\n”, V ((double)idr) * (double)idr);

The function V is the same as the interatomic potential function published on Phys. Rev. B 63, 224106 (2001), but I cannot figure out what does the multiplication mean in the “fprintf” part, if it is r*phi, it should be written as V((double)i*dr)*(i*dr) instead.

In summary, at least for the EAMs in the tools folder of LAMMPS, how is the interatomic potential function (phi) exactly expressed?

Thanks,

Jason