hybrid pair_style

Dear lammps users,

In my simulation I have Cu as the main lattice for which eam/alloy is used. Al solute atoms are located in the Cu lattice. I am going to use LJ potential to define the interaction between Al-Al and Al-Cu atoms.

I used these command to apply hybrid pair_style:

pair_style hybrid eam/alloy lj/cut 8.0
pair_coeff * * eam/alloy Cu01.eam.alloy Cu
pair_coeff 2 2 lj/cut 0.392 2.620
pair_coeff 1 2 lj/cut 0.40041 2.479

error is: Incorrect args for pair coefficients

when I changed the first pair_coeff to: pair_coeff * * eam/alloy Cu01.eam.alloy Cu Cu, everything works but I am wondering that atom type 1 and 2 are Cu and atom type 3 is different. So the next two command lines overwrite the first pair_coeff. when I change the last two lines to:

pair_coeff 3 3 lj/cut 0.392 2.620
pair_coeff 1*2 3 lj/cut 0.40041 2.479

the same error is seen.

could you please give me a hint to solve this problem?

Thanks,
Iman.

Dear lammps users,
In my simulation I have Cu as the main lattice for which eam/alloy is
used. Al solute atoms are located in the Cu lattice. I am going to use LJ
potential to define the interaction between Al-Al and Al-Cu atoms.
I used these command to apply hybrid pair_style:
pair_style hybrid eam/alloy lj/cut 8.0
pair_coeff * * eam/alloy Cu01.eam.alloy Cu
pair_coeff 2 2 lj/cut 0.392 2.620
pair_coeff 1 2 lj/cut 0.40041 2.479
error is: Incorrect args for pair coefficients
when I changed the first pair_coeff to: pair_coeff * * eam/alloy
Cu01.eam.alloy Cu Cu, everything works but I am wondering that atom type 1
and 2 are Cu and atom type 3 is different. So the next two command lines
overwrite the first pair_coeff. when I change the last two lines to:
pair_coeff 3 3 lj/cut 0.392 2.620
pair_coeff 1*2 3 lj/cut 0.40041 2.479
the same error is seen.
could you please give me a hint to solve this problem?

have a look at the eam/alloy example (using nickel) on this page:

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

axel.

Either your system has 2 atom types or it has 3. The pair_coeff command
for eam/alloy requires a certain number of params that depends on the 2 or 3.
If you don't do it right, you get an error. You can use a NULL for an atom
type that will be specified by another pair coeff command. See the pair style
EAM doc page.

Steve