Density-functional calculation of van der Waals forces for free-electron-like surfaces - art. no. 195414

A recently proposed general density functional for asymptotic van der Waals forces is used to calculate van der Waals coefficients and reference-plane positions for realistic low-indexed Al surfaces. Results are given for a n umber of atoms and molecules outside the surfaces, as well as for the inter action between the surfaces themselves. The densities and static image-plan e positions that are needed as input in the van der Waals functional are ca lculated self-consistently within density-functional theory using the gener alized-gradient approximation, pseudopotentials, and plane waves. This stud y shows that the van der Waals density functional is applicable to realisti c surfaces. The need for physically correct surface models, especially for open surfaces, is also illustrated. Finally the parameters for the anisotro pic interaction of O-2 with Al are calculated.