title: Comparative modelling of chemical ordering in palladium-iridium nanoalloys.
abstract: Chemical ordering in "magic-number" palladium-iridium nanoalloys has been studied by means of density functional theory (DFT) computations, and compared to those obtained by the Free Energy Concentration Expansion Method (FCEM) using derived coordination dependent bond energy variations (CBEV), and by the Birmingham Cluster Genetic Algorithm using the Gupta potential. Several compositions have been studied for 38- and 79-atom particles as well as the site preference for a single Ir dopant atom in the 201-atom truncated octahedron (TO). The 79- and 38-atom nanoalloy homotops predicted for the TO by the FCEM/CBEV are shown to be, respectively, the global minima and competitive low energy minima. Significant reordering of minima predicted by the Gupta potential is seen after reoptimisation at the DFT level.
authors.affiliation: School of Chemistry, University of Birmingham, Birmingham B15 2TT, United Kingdom.
authors.forename: Jack B A
authors.initials: JB
authors.lastname: Davis
authors.affiliation: School of Chemistry, University of Birmingham, Birmingham B15 2TT, United Kingdom.
authors.forename: Roy L
authors.initials: RL
authors.lastname: Johnston
authors.affiliation: Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Leonid
authors.initials: L
authors.lastname: Rubinovich
authors.affiliation: Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
authors.forename: Micha
authors.initials: M
authors.lastname: Polak