Empirical oscillating potentials for alloys from ab-initio fits and the prediction of quasicrystal-related structures in the Al-Cu-Sc system

TL;DR

This paper develops empirical oscillating potentials fitted to ab-initio data, enabling accurate modeling of complex alloy structures and predicting quasicrystal-related phases in the Al-Cu-Sc system.

Contribution

It introduces a simple six-parameter pair potential with Friedel oscillations derived from ab-initio data, facilitating structure prediction of complex alloys.

Findings

Accurate pair potentials for complex intermetallics

Successful prediction of quasicrystal-related structures

Method enables discovery of large-unit-cell structures

Abstract

By fitting to a database of ab-initio forces and energies, we can extract pair potentials for alloys, with a simple six-parameter analytic form including Friedel oscillations, which give a remarkably faithful account of many complex intermetallic compounds. Furthermore, such potentials are combined with a method of discovering complex zero-temperature structures with hundreds of atoms per cell, given only the composition and the con- straint of known lattice parameters, using molecular-dynamics quenches. We apply this approach to structure prediction in the Al-Cu-Sc quasicrystal-related system.