title: Graphene on Ir(111): physisorption with chemical modulation.
abstract: The nonlocal van der Waals density functional approach is applied to calculate the binding of graphene to Ir(111). The precise agreement of the calculated mean height h = 3.41  Å of the C atoms with their mean height h = (3.38±0.04)  Å as measured by the x-ray standing wave technique provides a benchmark for the applicability of the nonlocal functional. We find bonding of graphene to Ir(111) to be due to the van der Waals interaction with an antibonding average contribution from chemical interaction. Despite its globally repulsive character, in certain areas of the large graphene moiré unit cell charge accumulation between Ir substrate and graphene C atoms is observed, signaling a weak covalent bond formation.
authors.affiliation: II. Physikalisches Institut, Universität zu Köln, 50937 Köln, Germany. busse@ph2.uni-koeln.de
authors.forename: Carsten
authors.initials: C
authors.lastname: Busse
authors.forename: Predrag
authors.initials: P
authors.lastname: Lazić
authors.forename: Rabie
authors.initials: R
authors.lastname: Djemour
authors.forename: Johann
authors.initials: J
authors.lastname: Coraux
authors.forename: Timm
authors.initials: T
authors.lastname: Gerber
authors.forename: Nicolae
authors.initials: N
authors.lastname: Atodiresei
authors.forename: Vasile
authors.initials: V
authors.lastname: Caciuc
authors.forename: Radovan
authors.initials: R
authors.lastname: Brako
authors.forename: Alpha T
authors.initials: AT
authors.lastname: N'Diaye
authors.forename: Stefan
authors.initials: S
authors.lastname: Blügel
authors.forename: Jörg
authors.initials: J
authors.lastname: Zegenhagen
authors.forename: Thomas
authors.initials: T
authors.lastname: Michely