On the Lennard–Jones EAM potential

Abstract

We describe a simple two–parameter analytic model, based on the embedded–atom–method formalism, that extends a short range Lennard–Jones potential into the many–body regime. We demonstrate that this is a first step toward a minimalist treatment of real materials with negligible angular forces. The ground–state structures in this model include all the common phases. In this framework, properties of a face–centred cubic (FCC) material such as temperature dependence of free energy, melting point, thermal expansion coefficients, Grüneisen parameters, elastic constants and defect properties are calculated as a function of the many–body parameters A and β. These properties are then expressed as analytic functions of A and β, as perturbations of the classical Lennard–Jones pair potential. Addition of the many–body effects to the classical Lennard–Jones pair potential brings the computed material properties to within the range of their experimental values for many FCC metals.