title: Physisorption-induced C-H bond elongation in methane.
abstract: Physisorption of methane to a Pt surface was studied by x-ray absorption spectroscopy in combination with density functional theory spectrum calculations. The experiment shows new electronic states appearing upon physisorption. We find that these states are due to orbital mixing causing charge polarization as a means to minimize Pauli repulsion. The results can be explained by elongation of 1 C-H bond by 0.09 A in the physisorbed state even though no covalent chemical bond is formed.
authors.affiliation: Stockholm University, AlbaNova University Center, Fysikum, SE-106 91 Stockholm, Sweden.
authors.forename: H
authors.initials: H
authors.lastname: Oström
authors.forename: H
authors.initials: H
authors.lastname: Ogasawara
authors.forename: L-A
authors.initials: LA
authors.lastname: Näslund
authors.forename: L G M
authors.initials: LG
authors.lastname: Pettersson
authors.forename: A
authors.initials: A
authors.lastname: Nilsson