Charge and Compositional Effects on the 2D-3D Transition in Octameric AgAu Clusters
Artikel i vetenskaplig tidskrift, 2016

The unbiased density functional-based Birmingham Cluster Genetic Algorithm is employed to locate the global minima of all neutral and mono-ionic silver-gold octamer clusters. Structural, energetic and electronic trends are determined across the series, in order to clarify the role of composition and charge on the position of the 2D-3D transition in ultrasmall coinage metal systems. Our calculations indicate a preference for three dimensional structures at high silver concentrations, which varies significantly with charge. The minimum in composition dependent mixing energies is independent of the charge, however, with a preference tor the maximally mixed clusters, AgiAii4v for all charge states v. The sensitivity of isomeric preference to v is found to he greater for electron-rich and electron-deficient clusters, implying a complexity of unambiguous determination of cluster motifs in related experiments. Vertical ionization potentials and detachment energies are calculated to probe electronic behaviour, providing numerical predictions for future spectroscopic studies.

Range-Separated DFT

Ionization Potentials

Genetic Algorithm

Global Optimisation

Bimetallic Clusters

Författare

Christopher Heard

Chalmers, Fysik, Kemisk fysik

A. Shayeghi

Technische Universität Darmstadt

R. Schafer

Technische Universität Darmstadt

R. L. Johnston

University of Birmingham

Zeitschrift für Physikalische Chemie

0942-9352 (ISSN)

Vol. 230 955-975

Ämneskategorier

Fysikalisk kemi

DOI

10.1515/zpch-2015-0721