Theoretical investigation on the stability, structural evolution, and low-energy isomer identification of polyicosahedral Cu-Ag-Au nanoalloys: A DFT study

Abstract

In this study, Cu-Ag-Au nanoalloys have been investigated theoretically using the Gupta potential and the Monte Carlo BH algorithm. The global minimum structures and the first five isomers have been found for all possible compositions of 19, 23, 26, 38 and, 55 atom nanoalloys. For each size and all possible compositions, the global minimum structures and isomers have been re-optimized by DFT calculations. Our general finding is that in isomers and the GM structures, while the Cu atoms lie predominantly on the interior sites of the nanoalloy, the Ag and Au atoms mostly occupy the surface. Additionally, excess energies of DFT and Gupta levels of Cu-Ag-Au nanoalloys have also been compared. As a result, it has been found that excess energy variations at DFT and Gupta levels do not agree except for 19 atoms Cu-Ag-Au nanoalloys.