A fundamental understanding of the physical and chemical properties of gold clusters, namely, the size
dependence of these properties, is necessary for developing wide range of gold clusters’ applications. Having this purpose
in mind, the structural and energetic properties, such as binding energies, relative stability and band gaps ΔEHL (HOMOLUMO
gaps) are evaluated. The gold clusters in a wide range of sizes, Aun (n=2 - 2016), were constructed and studied by
Density Functional Theory and Extended Hückel Theory approaches. It was shown that the high values of ΔEHL for the
clusters with n= 2, 6, 8, 20 correlate with the highest stability. This finding explains the existence of magic numbers for
gold clusters. The 20 atom tetrahedral cluster stands out as particularly stable, comparing to the other small clusters. The
binding energy EB is found to increase with the cluster size. The second difference in energy - Δ2E(n) value is used as the
criterion of stability, in addition to ΔEHL and also shows a tendency to increase with the cluster size. This behavior
suggests a transition of larger clusters towards bulk metallic properties. Both curves - Δ2E(n) and ΔEHL show sharp
transformation from high values to close to 0 eV at n=252-504 cluster sizes (it relates to ca 2 nm cluster size).
Keywords: Gold, Clusters, ab initio, Hückel, DFT, Nanoparticle, Modeling.
Rights & PermissionsPrintExport