1. Introduction to LI-MEAM

Lattice Inversion Modified Embedded Atom Method (LI-MEAM) is a simplified version of the original MEAM models by removing the complex many-body screening function and including the interactions from more than the second nearest neighbors via Chen-Mobius lattice inversion method. LI-MEAM provides transparent physics, which can be viewed as a direct extension of EAM by considering the directional partial electron densities. Also, the number of adjustable parameters has been reduced.

LI-MEAM has been applied to a series of bcc and fcc elements and shown competitive results compared with previous MEAM models.

2. How to install LI-MEAM?

LI-MEAM is developed based on LAMMPS. So before you use LI-MEAM, you may have to learn something about LAMMPS firstly, such as how to install LAMMPS, how to use LAMMPS, etc.

After that, you can download the relevant files with LI-MEAM by clicking the following link:

After you have downloaded and unpackaged the package, you may obtain a folder containing the following files:

inv_bcc.txt
pair_meam.cpp
pair_meam.h
README.txt
meam
--meam_cleanup.F
--meam_data.F
--meam_dens_final.F
--meam_dens_init.F
--meam_force.F
--meam_setup_done.F
--meam_setup_global.F
--meam_setup_param.F

LI-MEAM is developed as an direct substitution of the original MEAM. It means:

  1. There is nothing different for the installation of LI-MEAM.
  2. The original MEAM in LAMMPS will be replaced by LI-MEAM.

So it's recommended that you can install LI-MEAM based on a copy of LAMMPS.

The following are the detail steps:

1. copy pair_meam.cpp, pair_meam.h to the scr directory of LAMMPS, like

$ cp pair_meam.cpp pair_meam.h ~/lammps/src/

2. copy all the files under the folder *meam* to the meam directory, like

$ cp ./meam/* ~/lammps/lib/meam/

3. install LAMMPS with meam package included, like

$ cd ~/lammps/
$ make yes-meam
$ make g++

If you have completed all the above steps with no errors, you should have finished the installation of LAMMPS with LI-MEAM package successfully.

3. How to use LI-MEAM?

The commands to used LI-MEAM in LAMMPS are totally the same with the original MEAM, except the potential parameters might be different, like

pair_style meam
pair_coeff * * library.meam Fe single.meam Fe

inv_bcc.txt stores the coefficients for bcc associated with lattice inversion. It will be called by the program so as to run lattice inversion, so you need to copy it to your directory you run LAMMPS, like

$ cp inv_bcc.txt WORK_DIR