Berlin 2015 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 39: Methods in Computational Materials Modelling V: Kinetics and Beyond DFT

MM 39.5: Vortrag

Mittwoch, 18. März 2015, 17:00–17:15, H 0106

Random phase approximation up to the melting point: The impact of anharmonicity and many-body effects on the thermodynamics of Au — Blazej Grabowski, •Stefan Wippermann, Albert Glensk, Tilmann Hickel, and Jörg Neugebauer — Max-Planck-Institut für Eisenforschung GmbH, D-40237 Düsseldorf, Germany

Triggered by the Materials Genome Initiative the development of ab initio based materials databases has gained immense momentum. A crucial requirement is that the databases reliably provide quantitatively accurate data. However, the application of generalized-gradient corrected functionals within standard density-functional theory results in a dramatic failure for e. g. the heat capacity of Au, leading to divergent thermodynamic properties well below the melting point.

Here we present an extension of the upsampled thermodynamic integration using Langevin dynamics (UP-TILD) technique to compute accurate finite temperature properties including many-body effects. We employ the random phase approximation (RPA) within the adiabatic connection fluctuation dissipation (ACFD) framework, showing that the inclusion of many-body effects leads to a stabilization and to an excellent agreement with experiment. The study demonstrates the capabilities of the RPA – previously confined to T=0K – at finite temperatures.