Regensburg 2010 – scientific programme

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O: Fachverband Oberflächenphysik

O 55: Density functional theory and beyond for real materials II

O 55.8: Talk

Wednesday, March 24, 2010, 16:45–17:00, H34

On the way to exact-exchange quality from a semi-local functional — •Andreas Karolewski and Stephan Kümmel — Theoretische Physik, Universität Bayreuth, 95440 Bayreuth, Germany

In this talk we discuss an approach for constructing a semi-local ``ab initio'' exchange functional that promises to incorporate many of the attractive features of exact exchange at low computational cost. A particularly relevant example is predicting the polarizabilities of extended systems. This has been a long-standing problem in density functional theory. We show that the new approach predicts the polarizabilities of extended conjugated molecules with much better accuracy than typical semi-local functionals.

The common approach of functional development is starting with an expression for the exchange correlation energy and calculating the exchange correlation potential via the functional derivative. In contrast, we start with an effective approximation for the exchange potential and show that it predicts the polarizabilities with much better accuracy than typical semi-local functionals. Furthermore we discuss a way of finding a corresponding energy functional.