Berlin 2008 – wissenschaftliches Programm

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SYEC: Symposium Exact-exchange and hybrid functionals meet quasiparticle energy calculations

SYEC 1: Exact-exchange and hybrid functionals meet quasiparticle energy calculations I

SYEC 1.4: Hauptvortrag

Donnerstag, 28. Februar 2008, 11:00–11:30, A 151

Electronic properties of solids within a GW-based DFT scheme: Local versus non-local hybrid functionals — •Angel Rubio — European Theoretical Spectroscopy Facility (ETSF), Dpto Fisica de Materiales, Universidad del Pais Vasco, Centro Mixto CSIC-UPV, San Sebastian, Spain

In this talk we will show alternative treating of correlation effects within a density-functional-based approach based on the adiabatic-connection fluctuation-dissipation theorem (ACFDT) and the linearise Sham-Schlüter. In this context we have calculated the RPA energies as well as the structural properties of simple solids (Si, NaCl). As expected, there are minor differences between the KS-LDA and the RPA results. However, in model layered systems, where layer-layer interactions are very weak, there are evident discrepancies due to the presence of long-ranged correlations. We will discuss the implications for the gap and optical properties in a KS and generalised KS formalisms.

Work done in collaboration with M. Gruning, A. Marini and P. Garcia-Gonzalez. References: Advanced Correlation Functionals: Application to Bulk Materials and Localized Systems P. Garcia-González, J.J. Fernandez, A. Marini and A. Rubio, J. Phys. Chem. B , (2007); First-Principle Description of Correlation Effects in Layered Materials; A. Marini, P. García-González and A. Rubio Phys. Rev. Letts 96, ); Density functionals from many-body perturbation theory: the bandgap for semiconductors and insulators M. Grüning, A. Marini and A. Rubio J. Chem. Phys. 124, (2006), and Effect of spatial nonlocality on the density functional band gap, Phys. Rev. B 74, (2006)