Regensburg 2007 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 17: Poster Session I (Nanostructures at Surfaces; Metal Substrates: Epitaxy and Growth; Methods: Scanning Probe Techniques; Phase Transitions)

O 17.27: Poster

Montag, 26. März 2007, 17:30–20:30, Poster C

CO ADSORPTION ON METAL SURFACES: A HYBRID DENSITY FUNCTIONAL STUDY WITH PLANE WAVE BASIS SET — •alessandro stroppa, konstantinos termentzidis, joachim paier, and georg kresse — Institut für Materialphysik, Universität Wien, Sensengasse 8/12, 1090 Wien, Austria

We present a detailed study of the adsorption of CO on Cu, Rh, and Pt (111) surfaces in top and hollow sites. The study has been performed with a gradient corrected functional (PBE) and PBE0 and HSE03 hybrid Hartree-Fock density functionals within the framework of generalized Kohn-Sham density functional theory using a plane-wave basis set. As expected, the gradient corrected functional shows the tendency to favor the hollow sites, at variance with experimental findings that give the top site as the most stable adsorption site. The PBE0 and HSE03 functionals reduce this tendency. Indeed, they predict the correct adsorption site for Cu and Rh but fail for Pt. But even in this case, the hybrid functional destabilizes the hollow site by 50 meV compared to the GGA description. This suggests that hybrid functionals give an overall better description of the chemisorption of CO molecules on metal surfaces, but, in general, they still do not predict the correct adsorption site. The results of the total energy calculations are presented along with an analysis of the projected density of states and Loewdin charges