Density functional theory investigation of Stability and Reactivity in Au-Cu nanoclusters of type AumCun (m+n=13)

Pure and doped gold clusters have been of immense use in catalyzing reactions and assembling nano functional materials for various applications. In this work, we focus on stepwise doping of copper atoms in pure 13 atom gold clusters, thereby the cluster composition investigated is Aum Cun (m+n = 13). We employ the genetic algorithm ABCluster which uses the artificial bee colony (ABC) algorithm to model the various isomers of each cluster composition. We applied DFT functional PBE and LANL2DZ basis functions to model the potential energy surface of the clusters. The minimum energy isomer of each composition was then used to study various molecular properties like binding energy, second order difference in energy, vertical ionization energy, vertical electron affinity, HOMO-LUMO gap, second order difference in energy. Odd-even oscillations in the molecular properties reveal the competing shell closing stabilization between Cu and Au atoms. To compare the activity of the clusters in catalysis, adsorption studies of small molecules O2 and C2H2 were done. This work aims to study the entire range of Cu doped 13 atom Au cluster compositions.