Abstract
The adsorption of 1,4-benzenediamine (BDA) on the Au(111) surface and azobenzene on the
Ag(111) surface is investigated using density functional theory (DFT) with a non-local density functional
(vdW-DF) and a semi-local Perdew-Burke-Ernzerhof (PBE) functional. For BDA on Au(111),
the inclusion of London dispersion interactions not only dramatically enhances the moleculesubstrate
binding, resulting in adsorption energies consistent with experimental results, but also
signi cantly alters the BDA binding geometry. For azobenzene on Ag(111), the vdW-DF produces
superior adsorption energies compared to those obtained with other dispersion corrected DFT approaches.
These results provide evidence for the applicability of the vdW-DF method and serves as
a practical benchmark for the investigation of molecules adsorbed on noble metal surfaces.
