Electronic Properties of Molecules and Surfaces with a Self-Consistent Interatomic van der Waals Density Functional

How strong is the effect of van der Waals (vdW) interactions on the electronic properties of molecules\udand extended systems? To answer this question, we derived a fully self-consistent implementation of the\uddensity-dependent interatomic vdW functional of Tkatchenko and Scheffler [Phys. Rev. Lett. 102, 073005\ud(2009)]. Not surprisingly, vdW self-consistency leads to tiny modifications of the structure, stability, and\udelectronic properties of molecular dimers and crystals. However, unexpectedly large effects were found in\udthe binding energies, distances, and electrostatic moments of highly polarizable alkali-metal dimers. Most\udimportantly, vdW interactions induced complex and sizable electronic charge redistribution in the vicinity\udof metallic surfaces and at organic-metal interfaces. As a result, a substantial influence on the computed\udwork functions was found, revealing a nontrivial connection between electrostatics and long-range electron\udcorrelation effects