Use MEAM in MD++

This tutorial describes how to use the modified embedded-atom method (MEAM) potential in MD++. The MEAM potential was originally developed by Dr. Mike Baskes,

Modified embedded-atom potentials for cubic materials and impurities, Physical Review B, 46, 2727 (1992).

Since then MEAM potentials for many elements, as well as binary and ternary alloy systems have been developed. The MEAM potentials allows us to quickly set up a model for a wide range of materials systems. MEAM has also been implemented in LAMMPS, whose subroutines have been used in the MEAM implementation in MD++.

Through some examples, we will describe how to use MEAM in MD++ to model a binary system, as well as allowing the simulation cell to change its shape.

Download files

First, you need to install MD++ on your computer by following the instructions on MD++ Manuals.

Second, copy file meam_test.tcl to your input file directory of MD++. You can do so by the following commands (assuming you have installed MD++ in ~/Codes/MD++).

 export MDPP=~/Codes/MD++
 mkdir -p ${MDPP}/scripts/work/meam
 cd ${MDPP}/scripts/work/meam
 wget http://micro.stanford.edu/mediawiki-1.11.0/images/Meam_test.tcl.txt -O meam_test.tcl

Compile executable file

There are several MEAM implementations in MD++,

meam-lammps         - MEAM (taken from lammps)
meam-baskes         - MEAM (taken from Baskes's code dynamo)
meam                - MEAM (directly implemented in MD++)

meam-lammps is the one that is most extensively tested. We will use meam-lammps exclusively in the following discussions.

You can compile meam-lammps by typing

 cd ${MDPP}
 make meam-lammps build=R SYS=su-ahpcrc

If compilation is successful, this will create binary file meam-lammps_su-ahpcrc file in your ${MDPP}/bin directory. (su-ahpcrc is one of our computer clusters at Stanford.)

Relaxation with fixed box

Relaxation at constant stress

MD in NVT ensemble

MD in NσT ensemble