Regarding potential of an alloy

Hello All,

I am using Copper and Beryllium in my system. EAM potential is available for Cu (Cu_u3.eam).
For Be, Be.eam.alloy potential file is available. Can i use it for CuBe system together? Lammps can directly give the cross-interaction if individual EAM funcfl files are available. However for Be, alloy file exists which is in setfl format, although it contains only single element.

Could you suggest some way to make CuBe cross-interaction?


You’ll have to read about the format for the potential
files on the pair_eam.html doc page. You need
an alloy-format (setfl) file that contains params
for both elements and the mixing terms. You may
have to create it by hand if you can’t find it on
a web site - e.g. the NIST site mentioned on the
doc page.


Hi steve and all
Thanks for the reply.
If eam.alloy file is available for both the elements, Is there a way to create cross interaction between the two.

As I have Cu.eam.alloy and Be.eam.alloy file, the format is same for both the potentials now.

As the pair eam doc page explains, alloy (setfl) files have

interactinons for the Cu/Cu, Be/Be, and Cu/Be pairs in them.

LAMMPS won’t guess Cu/Be for you, you have to provide it.

That’s the point of an alloy setfl file.

If you want to provide 2 single-element (funcfl) files, one for Cu

and one for Be, then LAMMPS will mix them to produce Cu/Be.

But funcfl and setfl files are different formats. You’d have to

create a funcfl file from each of your setfl files.

Again, all this info is on the pair eam doc page.