Regensburg 2010 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 4: Topical Session Designing Innovative Structural Materials and Steels II
MM 4.2: Talk
Monday, March 22, 2010, 11:45–12:00, H4
From DFT via TB to BOP: Atomistic simulations with ab-initio derived bond order potentials — •Martin Reese1,2, Matous Mrovec1,2, Bernd Meyer3, and Christian Elsässer1,2 — 1Fraunhofer-Institut für Werkstoffmechanik IWM, Freiburg — 2IZBS, Universität Karlsruhe — 3ICMM, Universität Erlangen-Nürnberg
Nanostructered composites of crystalline and amorphous carbides and nitrides can yield materials that reach the limit of super-hardness. These unusual properties are related to a subtle balance between the amorphous and crystalline phases and the properties of interfaces at the nanometer level. Atomistic simulations can significantly contribute to a better understanding of these complex materials provided that the employed models of atomic interactions are robust and reliable.
In this work we present a bottom-up procedure, which enables a development of ab-initio derived analytic bond-order potentials (BOPs). First, by projecting the self-consistent electronic wave functions from density functional theory onto a minimum basis of atomic orbitals we construct tight-binding models, which retain the crucial aspects of electronic structure. These are then further coarse-grained into a form of the interatomic BOPs, which describe correctly the interatomic bonding and are computationally efficient.
The procedure will be demonstrated for C-H and C-Si systems. The performance and transferability of the constructed BOPs on various complex structures will be presented.