Dresden 2020 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 36: Topical Session: Interface-dominated phenomena - Theoretical Approaches
MM 36.2: Talk
Wednesday, March 18, 2020, 12:15–12:30, IFW A
Towards large-scale atomistic calculations with quantum-mechanical accuracy: the QM/MM route — •Gehringer Dominik1, Liam Huber2, Jörg Neugebauer2, and David Holec1 — 1Department Materials Science, Montanuniversität Leoben, Franz-Josef-Straße 18, 8700 Leoben — 2Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf
Although ab-initio methods such as Density Functional Theory (DFT) provide a powerful tool to investigate materials science problems, they are also a limiting factor in terms of tractable system sizes, especially when one moves on to extended defects (interfaces, grain boundaries, dislocations). In constrast to DFT molecular dynamics (MD) is also well suited to properly describe temperature and mechanical properties, since simulations can handle thousands of atoms needed for describing extended defects. On the other hand, since in MD simulations do not consider the electronic structure but rather rely on interatomic potentials, the accessible chemistry is restricted by the availability of those. This is a limiting factor for e.g. segregation studies.
In the present contribution we will describe our developments for linking quantum mechanical calculations with molecular mechanics. While MM is applied to matrix regions, QM is used to treat chemical impurities and extended defects such as interfaces for which interatomic potentials are not available. After introducing the methodology and its implementation within the pyiron framework, we will show an example of linking LAMMPS and VASP calculations on an example of segregation to phase boundaries in γ/α2 structured TiAl alloys.