Dresden 2009 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 42: Poster Session II (Nanostructures at surfaces: arrays; Nanostructures at surfaces: Dots, particles, clusters; Nanostructures at surfaces: Other; Nanostructures at surfaces: Wires, tubes; Metal substrates: Adsorption of O and/or H; Metal substrates: Clean surfaces; Metal substrates: Adsorption of organic/bio moledules; Metal substrates: Solid-liquid interfaces; Metal substrates: Adsorption of inorganic molecules; Metal substrates: Epitaxy and growth; Heterogeneous catalysis; Surface chemical reactions; Ab-initio approaches to excitations in condensed matter; Organic, polymeric, biomolecular films– also with adsorbates; Particles and clusters)

O 42.104: Poster

Mittwoch, 25. März 2009, 17:45–20:30, P2

2nd-order Møller-Plesset perturbation theory applied to extended systems — •Andreas Grüneis, Martijn Marsman, and Georg Kresse — Faculty of Physics, University Vienna, and Center for Computational Materials Science, Sensengasse 8/12, A-1090, Vienna, Austria

The use of wave function based methods, such as Møller-Plesset perturbation theory, to add electronic correlation to the Hartree-Fock (HF) approximation is common practice in the computational quantum chemistry of molecular systems. Due to the computational cost involved, however, these methods have hardly been applied to extended systems.

Recently, we have implemented 2nd-order Moller-Plesset (MP2) perturbation theory within the framework of the full-potential Projector-Augmented-Wave (PAW) method, using periodic boundary conditions and a plane wave basis set.

The present implementation allows for the calculation of total energies as well as quasiparticle energies. In order to determine the accuracy of this method we calculated lattice constants, bulk moduli, band gaps, and atomization energies of several semiconducting and insulating systems, including hexagonal Ice. Compared to HF, HF+MP2 yields an improved description of the aforementioned structural properties.

Regarding band gaps, HF+MP2 band gaps present an improvement over the corresponding HF results. Nevertheless, the underestimated static dielectric screening properties of the employed HF wave functions are reflected in underestimated band gaps.