Berlin 2008 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 86: Oxides and Insulators: Adsorption
O 86.4: Vortrag
Freitag, 29. Februar 2008, 10:15–10:30, MA 141
Wavefunction-based ab-initio results for the adsorption of CO on Ceria (110) surface — Carsten Müller1, Björn Herschend1, •Beate Paulus2, and Kersti Hermansson1 — 1Department of Materials Chemistry, Uppsala University, Lägerhyddsvägen 1, 75121 Uppsala, Sweden — 2Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin
For the ab-initio description of the adsorption process on surfaces it is necessary to model all interactions on the same theoretical footing. The standard density functional methods have their difficulties with describing dispersion forces. But especially for the physisorption, where no covalent bonds are formed between the adsorbant and the surface these interactions are essential. They can only well described with wavefunction based correlation methods. With the method of increments [1] it is possible to apply these methods to extended systems. Here we want to present the first application to an adsorption process. As example we have chosen CO on ceria 110 surface. The idea is to partition the correlation part of the adsorption energy according to localized orbital groups of the adsorbant and the individual atoms in the surface. The main part of the binding are the correlation energies of the absorbant with the different atoms of the surface. Therefore, with the method of increments it is not only possible to yield highly accurate results for the adsorption energy, but also gain information about the individual contributions to the adsorption.
[1] B. Paulus, Phys. Rep. 428, 1 (2006).