TY  - JOUR
AU  - Lazic, P.
AU  - Atodiresei, N.
AU  - Caciuc, V.
AU  - Brako, R.
AU  - Gumhalter, B.
AU  - Blügel, S.
TI  - Rationale for switching to nonlocal  functionals in density functional theory
JO  - Journal of physics / Condensed matter
VL  - 24
SN  - 0953-8984
CY  - Bristol
PB  - IOP Publ.
M1  - PreJuSER-22956
SP  - 424215
PY  - 2012
N1  - Record converted from VDB: 12.11.2012
AB  - Density functional theory (DFT) has been steadily improving over the past few decades, becoming the standard tool for electronic structure calculations. The early local functionals (LDA) were eventually replaced by more accurate semilocal functionals (GGA) which are in use today. A major persisting drawback is the lack of the nonlocal correlation which is at the core of dispersive (van der Waals) forces, so that a large and important class of systems remains outside the scope of DFT. The vdW-DF correlation functional of Langreth and Lundqvist, published in 2004, was the first nonlocal functional which could be easily implemented. Beyond expectations, the nonlocal functional has brought significant improvement to systems that were believed not to be sensitive to nonlocal correlations. In this paper, we use the example of graphene nanodomes growing on the Ir(111) surface, where with an increase of the size of the graphene islands the character of the bonding changes from strong chemisorption towards almost pure physisorption. We demonstrate how the seamless character of the vdW-DF functionals makes it possible to treat all regimes self-consistently, proving to be a systematic and consistent improvement of DFT regardless of the nature of bonding. We also discuss the typical surface science example of CO adsorption on (111) surfaces of metals, which shows that the nonlocal correlation may also be crucial for strongly chemisorbed systems. We briefly discuss open questions, in particular the choice of the most appropriate exchange part of the functional. As the vdW-DF begins to appear implemented self-consistently in a number of popular DFT codes, with numerical costs close to the GGA calculations, we draw the attention of the DFT community to the advantages and benefits of the adoption of this new class of functionals.
LB  - PUB:(DE-HGF)16
C6  - pmid:23032957
UR  - <Go to ISI:>//WOS:000309956300016
DO  - DOI:10.1088/0953-8984/24/42/424215
UR  - https://juser.fz-juelich.de/record/22956
ER  -