pair_style meam

Dear all,

I declared 2 atom Si type 1 and Pt type 2 and want to perform simulation with MEAM. Si and Pt are present in the library.meam file. I use windows version Oct 2015. The library.meam file is in the same directory as the input script file

I wrote (as in documentation) :

pair-style meam

pair_coeff * * library.meam Si Pt

And receive an error message : ERROR: Incorrect args for pair coefficients (…/pair_meam.cpp:354)

I do not understand what is wrong. I test with some other element present in the library file. If I use combination of EAM (Pt-Pt), Tersoff (Si-Si) and LJ (Pt-Si) it works.

The log.lammps file gives:

Dear all,

I declared 2 atom Si type 1 and Pt type 2 and want to perform simulation
with MEAM. Si and Pt are present in the library.meam file. I use windows
version Oct 2015. The library.meam file is in the same directory as the
input script file

I wrote (as in documentation) :

pair-style meam

pair_coeff * * library.meam Si Pt

And receive an error message : ERROR: Incorrect args for pair coefficients
(../pair_meam.cpp:354)

I do not understand what is wrong. I test with some other element present
in the library file. If I use combination of EAM (Pt-Pt), Tersoff (Si-Si)
and LJ (Pt-Si) it works.

​you are not following the syntax for pair style meam correctly. you only
specify the MEAM library and "extract" the elements that you want to use.
you are still missing the second (!) file name (which ​may be NULL) and the
mapping of the elements selected from the meam library to the LAMMPS type.
without a special parameter file the line in your input will have to be:

pair_coeff * * library.meam Si Pt NULL Si Pt

axel.

Thanks a lot J

I misunderstood the NULL term in the example : I expected it was another element not concerned by the MEAM interaction.

Regards

Pascal