Modified embedded-atom method interatomic potentials for the Mg-Al alloy system

We developed modified embedded-atom method (MEAM) interatomic potentials for the $\mathrm{Mg}\text{\ensuremath{-}}\mathrm{Al}$ alloy system using a first-principles method based on density functional theory (DFT). The materials parameters, such as the cohesive energy, equilibrium atomic volume, and bulk modulus, were used to determine the MEAM parameters. Face-centered cubic, hexagonal close packed, and cubic rock salt structures were used as the reference structures for Al, Mg, and $\mathrm{MgAl}$, respectively. The applicability of these MEAM potentials to atomistic simulations for investigating $\mathrm{Mg}\text{\ensuremath{-}}\mathrm{Al}$ alloys was demonstrated by performing simulations on Mg and Al atoms in a variety of geometries. These MEAM potentials were used to calculate the adsorption energies of Al and Mg atoms on $\mathrm{Al}\phantom{\rule{0.3em}{0ex}}(111)$ and $\mathrm{Mg}\phantom{\rule{0.3em}{0ex}}(0001)$ surfaces. The formation energies and geometries of various point defects, such as vacancies, interstitial defects, and substitutional defects, were also calculated. We found that the MEAM potentials give a better overall agreement with DFT calculations and experiments when compared against the previously published MEAM potentials.