[lammps-users] EAM potential file

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1

Dear all:
     I want to make my own EAM potential file for FeNi alloy. After read the pair_eam.cpp and the website
http://ceaspub.eas.asu.edu/cms/potentials/main/main.htm, I think the format of setfl file may be like this

Line 1 ~ 3 : comments
Line 4 : ntypes
Line 5 : nrho drho nr dr rcutoff
Line 6 : ielem(i) amass(i) blat(i) lat(i)
Line 7 : embedding function
    ...
Line z : electron density
    ...
Line x : ielem(j) amass(j) blat(j) lat(j)
Line x+1 : embedding function
    ...
Line y : electron density
    ...
Line p1 : pair potential between type1 and type1
    ...
Line p2 : pair potential between type2 and type1
   ...
Line p3 : pair potential between type2 and type 2

My question is what is the units of embedding function, is it ev?
In the pair potential, p = pair(r)*r, what is the units of pair(r) and r, is it ev and angstroms?

Does anyone know where can find more information about the format of setfl type file ?

Thanks very much!

                                                                   Yang

2

I don't know these units off the top of my head. The only way to be
sure is look in pair_eam.cpp and see how the read-in values are being
used. For EAM the LAMMPS units are eV for energy and Angstroms
for distance, but I think there are some conversion factors used in
the file, like for zr2. You could also email Stephen Foiles ([email protected]....)
who authored DYNAMO where the file format originated
and may be able to point you to a paper that describes the units.

Steve