Dresden 2009 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 18: Metal substrates: Adsorption of organic / bio molecules III

O 18.6: Vortrag

Dienstag, 24. März 2009, 11:45–12:00, SCH A118

Chemical versus van der Waals Interaction: The Role of the Heteroatom — •Nicolae Atodiresei, Vasile Caciuc, Predrag Lazić, and Stefan Blügel — Institut für Festkörperforschung (IFF), Forschungszentrum Jülich, 52425 Jülich, Germany

We performed first-principles calculations aimed to investigate the role of an heteroatom like N in the chemical and the long-range van der Waals (vdW) interactions for a flat adsorption of several π−conjugated molecules on the Cu(110) surface. To evaluate the dispersion effects we used an ab initio as well as a semiempirical method. A key result of our study is that a state of the art investigation of the bonding mechanism leading to a flat molecule−substrate adsorption geometry requires the use of both methods to correctly describe the geometry, the electronic structure and the correlation effects of the molecule−surface interface. Our study reveals that the molecule-surface vdW interactions involve not only π-like orbitals which are perpendicular to the molecular plane but also σ-like orbitals delocalized in the molecular plane.

Ref.

1. N. Atodiresei, V. Caciuc, H.-J. Franke and S. Blügel, Phys. Rev. B 78, 045411 (2008).

2. N. Atodiresei, V. Caciuc, P. Laźic, and S. Blügel, arXiv:0811.3082.