Figure 2.

Top: Adsorption structures of the benzene/Au(111) and benzene/Pt(111) systems, both at the so-called bri30° adsorption site, where 30° refers to the angle of the C–C bond relative to the close-packed metal rows. The indicated distances are obtained based on the PBE+vdW^surf optimized structures. Gray, yellow, cyan, and white spheres represent Pt, Au, C, and H atoms, respectively. Bottom: Adsorption energy −E_ad as a function of the adsorption height d for benzene on the Au(111) and Pt(111) surfaces from the PBE and PBE+vdW^surf methods (all carbon atoms are located at a distance d from the top metal layer). The experimentally derived binding distances and adsorption energies are indicated by yellow intervals (from refs (28, 43, 46, and 47)). Reproduced with permission from ref (48). Copyright 2012 American Physical Society.