7 Computational study of CunAgAu (n = 1–4) clusters invoking DFT based descriptors

Metallic clusters have shown potential uses in science and technology especially in the domain of photovoltaics, biomedical and catalysis. The noble metal based clusters like Cu, Ag, and Au exhibits notable structural, electronic and optical properties. In this work, we have examined physico-chemical behaviours of tri-metallic clusters CunAgAu (n = 1-4) by using density functional theory (DFT) technique. Conceptual DFT based descriptors of these clusters are calculated and analysed. HOMO-LUMO gap at n = 2, 3 and 4 are found as 1.667, 1.610 and 1.785 eV, respectively. It states that these clusters can be used in optoelectronic and photovoltaic devices. HOMO-LUMO energy gap, hardness and electronegativity of CunAgAu clusters exhibit an odd-even fluctuation behaviour with the cluster size, n. Molecular hardness of CunAgAu cluster shows linear relationship with energy gap whereas molecular softness exhibits an inverse relationship.