Empirical many-body interatomic potential for bcc transition metals

Abstract

A simple many-body interatomic potential is proposed. This is an empirical extension of the embedded-atom method (EAM). The EAM models the lattice energy and elastic compressibility using a pair interaction plus a many-body term. It does not include any contribution of many-body terms to the crystal elastic shear. This contribution is included in the model developed here. It implies a simplified treatment of the angularity inherent to covalent bonding in transition metals. A set of interatomic potentials is deduced for bcc Nb, Fe, and Cr. While in previous works in the literature the EAM has already been successfully applied to the fitting of interatomic potentials for Nb and Fe, this was not the case for Cr, for which the elastic-constant values implied a negative Cauchy pressure.

Atomistic modeling of interfaces and their impact on microstructure and properties

“…In addition, the many-body screening procedure of MEAM is replaced by a smooth cutoff including 4-6 coordination shells. The ADP method is similar to but more general than the embedded-defect method proposed by Pasianot et al [150]. The recently developed Au potential [151] is based on a similar angular-dependent format.…”

Simulating Interface Growth and Defect Generation in CZT – Simulation State of the Art and Known Gaps

“…Pasianot et al [267] added a new term in the form of total energy for the EAM to represent a many-body shear term related to bond angles in a global (average) sense. Zhang et al [268] modified Johnson's analytic EAM, in a similar way to Pasianot.…”

An Empirical Many-Body Potential for B2 FeAl

“…The most simple ones involve an additional 3 body non-central term [6], which was initially introduced as an angularly dependent correction for the density over a site [2,7]. However, as the system of interest is metallic, we preferred to confine to a form of potential already successhlly tested in such a context and chose an expression first proposed on more empirical grounds [8] and already known to be efficient for several elements (among which Cr also displays a negative Cauchy discrepancy). Following these authors, we thus write the energy of an assembly of atoms i as:…”