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The adsorption of benzene (C6H6) at the close-packed Cu(111) surface is a much studied model system for the interaction of larger ð conjugated molecules with solid surfaces [1]. At first glance a rather simple system, the suspected predominantly van der Waals type bonding at the extended metal surface poses a severe challenge for accurate first-principles calculations. Densityfunctional theory (DFT) with
presentday local and semilocal exchange correlation (xc) functionals is uncertain to properly account for this type of bonding, while the system sizes required to correctly grasp the metallic band structure
quickly become computationally untractable with correlated wave function techniques. We overcome
these limitations with a recently introduced "local xc correction" scheme [2], correcting the deficiencies in the adsorption energetics from present-day DFT xc functionals with hybrid functional and MøllerPlesset perturbation theory calculations. Building on the obtained binding energy curves at
the different levels of theory we attempt a discussion of the various contributions to the bonding at the
noble metal surface.
[1] S. Lukas, S. Vollmer, G. Witte and Ch. Wöll, J. Phys. Chem. 114, 10123 (2001). [2] Q.M. Hu, K. Reuter and M. Scheffler, Phys. Rev. Lett., 98, 176103 (2007). |
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