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EAM

EAM: Embedded Atom Method
Definition:A method to approximate the total energy of a random arrangement of atoms in a metal
Explanation:The energy of an atomic arrangement is given by a sum of electrostatic pair terms and an embedding function, which describes the local energy density. Equivalent to density functional theory (→DFT), EAM describes the system as a function of electron density, but under the approximation that the density of the whole system is a simple superposition of the local atomic densities. The EAM potential is widely used in molecular dynamics (→MD) simulations of metals.

For a EAM system with a single element, three functions are used to describe the system: (i) the embedding function, (ii) an electronic density function, and (iii) pair exchange potential. These functions are usually fitted to experimental or ab initio data.

The total energy form for the EAM potential is given as Eq. 1 below, where φij(rij) is the pair potential term describing electrostatic core-core repulsion, and the cohesive term, Fi(ni), describes the energy gain of the ion core when it is embedded in the energy density, ni, which is the superposition of the local energy densities ρj(rij).
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Diagram:


Gamma-surface of a Al EAM potential.
SFB-Link:The embedded atom method is used in MD simulations in part project A6 to determine grain boundary mobility values. It is also used in part project A10 in MD simulations to determine dislocation interaction maps.
References:Daw and Baskes, Phys Rev Lett, 50, 1285, 1983
Daw and Baskes, Phys Rev B, 29, 6443, 1984