Bengt I. Lundqvist

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A scheme within density functional theory is proposed that provides a practical way to generalize to unrestricted geometries the method applied with some success to layered geometries [Phys. Rev. Lett. 91, 126402 (2003)]]. It includes van der Waals forces in a seamless fashion. By expansion to second order in a carefully chosen quantity contained in the(More)
It is shown that it is now possible to include van der Waals (vdW) interactions via a nonempirical implementation of density functional (DF) theory to describe the correlation energy in electronic structure calculations on infinite systems of no particular symmetry. The vdW-DF theory [Phys. Rev. Lett. 92, 246401 (2004)] is applied to the adsorption of(More)
The details of a density functional that includes van der Waals (vdW) interactions are presented. In particular we give some key steps of the transition from a form for fully planar systems [Phys. Rev. B 62, 6997 (2000)] to a procedure for realistic layered compounds that have planar symmetry only on large distance scales, and which have strong covalent(More)
To understand sparse systems, we must account for both strong local atom bonds and weak nonlocal van der Waals forces between atoms separated by empty space. A fully nonlocal functional form [Phys. Rev. B 62, 6997 (2000)]] of density-functional theory (DFT) is applied here to the layered systems graphite, boron nitride, and molybdenum sulfide to compute(More)
Kyuho Lee,1 André K. Kelkkanen,2,3 Kristian Berland,3 Stig Andersson,4 David C. Langreth,1 Elsebeth Schröder,3 Bengt I. Lundqvist,2,3,5 and Per Hyldgaard3 1Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854-8019, USA 2Center for Atomic-scale Materials Design, Department of Physics, Technical University of Denmark, DK-2800(More)
In a framework for long-range density-functional theory we present a unified full-field treatment of the asymptotic van der Waals interaction for atoms, molecules, surfaces, and other objects. The only input needed consists of the electron densities of the interacting fragments and the static polarizability or the static image plane, which can be easily(More)
Interfaces are brought into focus by many materials phenomena, e.g., contacting, materials strength, and wetting. The class of interfaces includes ultra-high-vacuum surfaces, which provide a meeting place for numerous accurate experimental techniques and advanced theory. Such meetings stimulate detailed comparisons on the quantum level between experiment(More)
The applicability of density-functional theory is extended to the area of van der Waals interactions between macroscopic bodies, in particular between two parallel surfaces. It is shown how the strength and the asymptotic form, including the van der Waals planes for the surfaces can be calculated with the electronic densities and the static image planes of(More)
The microscopic mechanism behind the extraordinary ability of ceria to store, release, and transport oxygen is explained on the basis of first-principles quantum mechanical simulations. The oxygen-vacancy formation energy in ceria is calculated for different local environments. The reversible CeO2-Ce2O3 reduction transition associated with oxygen-vacancy(More)