Publication Status

Al-Mg MEAM potential and related study is published in Phys. Rev. B 75, 054106 (2007)

Description

Al-Mg potential has been developed based on the DFT results of several point defects and surface adsorptions, along with basic crystal structure parameters.

A detailed description of how to generate a MEAM potential is available in Phys. Rev. B 46, 2727-2742 (1992).

To use these potentials, follow LAMMPS instructions at http://www.lammps.org/.

Example Run

We use LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator) code to test the potentials. It is a open source code available at http://www.lammps.org/ for more information go to the web site.

The above potential file are in LAMMPS specific format.

To run Lammps with MEAM potentials you need three files (2 potential files as shown above, and one input file). If you want to specify the atomic positions in a separate file, then you need four files.

Input Files

• AlMg.library.meam
  This is one of the potential files. This specifies the parameters relating to pure elements of Aluminum and Magnesium. It is also possible to have parameters of other pure elements. That way you can have one library.meam file for all alloy potentials and have different files for parameters describing pair interactions between different elements.


• AlMg.meam
  This is one of the potential files. This defines parameters relevant to interactions between Aluminum and Magnesium atoms. Copy and paste the text in to a file named AlMg.meam


• AlMg.in.meam
  This is the file that has the input commands for LAMMPS to execute a run. Copy and paste the following text in to a file named AlMg.in.meam. The tag "pair_coeff" specifies the two potential files, AlMg.library.meam and AlMg.meam. If you want to change the names of the potential files, you also have to change their names here as well.


• Mg17Al12.pos
  This file contains the position of the atoms of the system that is going to be studied. Copy and paste it to a Mg17Al12.pos text file of your choice.

To execute the example run you should have AlMg.library.meam, AlMg.meam, Mg17Al12.pos, AlMg.in.meam in the same directory. If your LAMMPS executable is named lmp_exec then you can execute the following command to begin the run.

lmp_exec < AlMg.in.meam

Output Files

• AlMg.log.lammps
  contains data such as energy pressure temperature etc. of system specified itn the data.meam: This is the main output file from LAMMPS. It will information about contain minimization/molecular dynamics steps, physical properties of the system, error codes etc. You can customize what properties to output through LAMMPS commands


• AlMg.dump.meam
  contains the resulting structure (atomic positions) after every run of the system : In this case only the final timestep (33) is given here.