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MM: Fachverband Metall- und Materialphysik

MM 28: Intermetallic phases I

MM 28.1: Talk

Thursday, March 29, 2007, 10:15–10:30, H16

Empirical effective potentials for complex metallic alloys — •Peter Brommer and Franz Gähler — Universität Stuttgart, Institut für Theoretische und Angewandte Physik, 70550 Stuttgart

Complex metallic alloys (CMAs) comprise materials with promising physical properties. Due to the inherent disorder in these systems, the atomic structure is frequently not reliably known in all details. Atomistic computer simulations are an essential tool both for determining the precise atomic structure and for following the microscopic processes responsible for the macroscopic properties. Unfortunately, first-principles simulations cannot cope with the required system sizes and simulated times, and classical effective potentials are rarely available. We present a programme called potfit, which determines the parameters of a classical potential by matching it to a large number of reference quantities computed with first-principles methods. These quantities comprise cohesive energies, stresses and forces on individual atoms in a collection of suitable reference systems. Effective potentials for the MgZn, NbCr, CaCd and AlNiCo systems have successfully been constructed and used in molecular dynamics simulations.