Computational Exploration of the Nanogold Energy Landscape

TL;DR

This study uses density functional theory to analyze how size and shape influence the energy landscape of gold nanoclusters, revealing shape-dependent stability for different cluster sizes and exploring potential catalytic applications.

Contribution

It introduces a parametric shape interpolation between icosahedral and cuboctohedral gold clusters and systematically evaluates their binding energies across sizes.

Findings

Cuboctahedral clusters are more stable at 13 atoms.

Icosahedral clusters are more stable at 55 and 147 atoms.

Binding energy varies with shape and size, indicating shape-dependent stability.

Abstract

We use density functional theory to quantify finite size and shape effects for gold nanoclusters. We concentrate on the computation of binding energy as a function of bond length for icosahedral and cuboctohedral clusters. We find that the cuboctoheral gold clusters have lower energy for 13 atoms. For 55 atoms we find that the icosahedral gold clusters have lower binding energy. We also introduce a one parameter family of geometries that interpolate between the icosahedral and cuboctohedral clusters that is parametrized by an angle variable. We determine the binding energy dependence on shape as a function of the angle variable for 13 and 55 atom clusters with a minimum at the cuboctohedral point and icosahedral point respectively. We also compute the binding energy for the 147 atom gold nanocluster and show that the binding energy of the icosahedral cluster is lower than the 147 atom cuboctohedral gold cluster. We also compute the binding energy of the $Au_{55}O_2$ molecule with possible applications to catalysis.