Berlin 2012 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 55: Theoretical methods II
O 55.10: Vortrag
Mittwoch, 28. März 2012, 19:00–19:15, MA 043
Static and Frequency Dependent Dipole Polarizabilities from the Ground-State Electron Density — •Vivekanand Gobre1, Robert DiStasio Jr.2, Matthias Scheffler1, and Alexandre Tkatchenko1 — 1Fritz-Haber-Institut der MPG, Berlin, Germany — 2Princeton University, Princeton, NJ, USA
Molecular polarizability is an essential observable, and its accurate determination is important, e.g., for calculation of van der Waals interactions. Accurate polarizability calculations in principle require computationally expensive electronic structure methods with an explicit treatment of many-electron excitations. These methods can only be applied to systems with less than about 100 atoms. However, one is often faced with the problem of computing polarizabilities for large systems with thousands of atoms. We present a parameter-free computationally efficient approach to calculate accurate static and frequency dependent polarizabilities for molecules and non-metallic solids. Specifically, we link the TS-vdW [1] method, which accurately treats hybridization effects, with the self-consistent screening equation from classical electrodynamics [2]. Using only the electron density and reference data for the free atoms, we obtain an accuracy of about 7% for both static polarizabilities and van der Waals coefficients for a wide variety of systems. We illustrate the interplay of hybridization and long-range electrostatic screening effects for the polarizability of large proteins and condensed-matter systems. [1] A. Tkatchenko and M. Scheffler, PRL 102, 073005 (2009); [2] B. U. Felderhof, Physica 76, 486 (1974).