title: A van der Waals density functional study of adenine on graphene: single-molecular adsorption and overlayer binding.
abstract: The adsorption of an adenine molecule on graphene is studied using a first-principles van der Waals functional, vdW-DF (Dion et al 2004 Phys. Rev. Lett. 92 246401). The cohesive energy of an ordered adenine overlayer is also estimated. For the adsorption of a single molecule, we determine the optimal binding configuration and adsorption energy by translating and rotating the molecule. The adsorption energy for a single molecule of adenine is found to be 711 meV, which is close to the calculated adsorption energy of the similarly sized naphthalene. On the basis of the single-molecular binding configuration, we estimate the cohesive energy of a two-dimensional ordered overlayer. We find a significantly stronger binding energy for the ordered overlayer than for single-molecule adsorption.
authors.affiliation: Department of Microtechnology and Nanoscience, University of Technology, Göteborg, Sweden.
authors.forename: Kristian
authors.initials: K
authors.lastname: Berland
authors.forename: Svetla D
authors.initials: SD
authors.lastname: Chakarova-Käck
authors.forename: Valentino R
authors.initials: VR
authors.lastname: Cooper
authors.forename: David C
authors.initials: DC
authors.lastname: Langreth
authors.forename: Elsebeth
authors.initials: E
authors.lastname: Schröder
mesh_terms: D000225:Adenine / Q000737:chemistry*; D000327:Adsorption; D004735:Energy Transfer; D006108:Graphite / Q000737:chemistry*; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D036103:Nanotechnology / Q000295:instrumentation*; D011789:Quantum Theory; D013816:Thermodynamics
chemical_list: D006108:Graphite; D000225:Adenine