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O: Oberflächenphysik
O 12: Methods
O 12.5: Vortrag
Montag, 27. März 2006, 16:00–16:15, WIL B321
Van der Waals Interaction: A Universal Semiempirical Supplement to DFT Tested for Various Systems — •Frank Ortmann1, Wolf G. Schmidt2, and Friedhelm Bechstedt1 — 1Institut für Festkörpertheorie und -optik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena, Germany — 2Universität Paderborn, Fakultät für Naturwissenschaften, Theoretische Physik, Warburger Str. 100, 33100 Paderborn, Germany
Theoretical investigations of surface adsorbed molecules are generally carried out using Density Functional Theory within the Local Density Approximation (LDA) or the Generalized Gradient Approximation (GGA). One driving force for the adsorption process of molecules are van der Waals interactions (see [1] and [2]). Unfortunately LDA and GGA are incapable of accounting for long-range correlations for inhomogeneous systems by construction.
We supplement the DFT with a semiempirical long-range correlation term based on the London formula [3] for van der Waals interaction to cure this lack. Here we examine the transferability of the present approach to different structures and to investigate the universality with respect to the atom species under consideration.
[1] F. Ortmann and W. G. Schmidt and F. Bechstedt, Phys. Rev. Lett. 95, 186101 (2005)
[2] M. Preuss and W. G. Schmidt and F. Bechstedt, Phys. Rev. Lett. 94, 236102 (2005)
[3] F. London, Z. Phys. Chem. Abt. B11, 222 (1930)