RPBE-vdW Description of Benzene Adsorption on Au(111)

Density functional theory has become a popular methodology for the analysis of molecular adsorption on surfaces. Despite this popularity, there exist adsorption systems for which commonly used exchange-correlation functionals fail miserably. Particularly those systems where binding is due to van der Waals interactions. The adsorption of benzene on Au(111) is an often mentioned such system where standard density functionals predict a very weak adsorption or even a repulsion, whereas a significant adsorption is observed experimentally. We show that a considerable improvement in the description of the adsorption of benzene on Au(111) is obtained when using the so-called RPBE-vdW functional.