title: An ab initio study of van der Waals potential energy parameters for silver clusters.
abstract: We employ ab initio calculations of van der Waals complexes to study the potential energy parameters (C(6) coefficients) of van der Waals interactions for modeling of the adsorption of silver clusters on the graphite surface. Electronic structure calculations of the (Ag(2))(2), Ag(2)-H(2), and Ag(2)-C(6)H(6) complexes are performed using a coupled-cluster approach that includes single, double, and perturbative triple excitations (CCSD(T)), Møller-Plesset second-order perturbation theory (MP2), and spin-component-scaled MP2 (SCS-MP2) methods. Using the atom pair approximation, the C(6) coefficients for silver-silver, silver-hydrogen, and silver-carbon atom systems are obtained after subtracting the energies of quadrupole-quadrupole interactions from the total electronic energy.
authors.affiliation: Laboratory of Physical Chemistry, Department of Chemistry, University of Helsinki, P.O. Box 55 (A.I. Virtasen aukio 1), FIN-00014, Finland.
authors.forename: Vesa
authors.initials: V
authors.lastname: Hänninen
authors.forename: Markus
authors.initials: M
authors.lastname: Korpinen
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Ren
authors.forename: Robert
authors.initials: R
authors.lastname: Hinde
authors.forename: Lauri
authors.initials: L
authors.lastname: Halonen