Density Functional Theory Study of Structural, Electronic and Optical Properties of 13‐Atom Au‐Ag‐Cu Ternary Clusters

The structural, electronic, and optical properties of 13‐atom Au‐Ag‐Cu ternary clusters are systematically investigated using density functional theory (DFT). The results indicate that the structural configurations of Ag 11− n Cu 2 Au n ( n = 2, 3, 4, 5, 6, 7, 9), Ag 10− n Cu 3 Au n ( n = 3, 4, 6, 7, 8, 9), Ag 8− n Cu 5 Au n ( n = 4, 5, 6, 7), Ag 11− n Cu 1 Au n ( n = 8, 9), Ag 7− n Cu 6 Au n ( n = 5, 6), and Ag 6− n Cu 7 Au n ( n = 3, 5) clusters exhibit irregular structural configurations, while other ternary clusters exhibit icosahedral‐like geometries. In terms of stability, Ag 9 Cu 2 Au 2 , Ag 7 Cu 2 Au 4 , Ag 5 Cu 2 Au 6 , Ag 3 Cu 7 Au 3 , Ag 3 Cu 3 Au 7 , Ag 1 Cu 9 Au 3 , Ag 1 Cu 6 Au 6 , and Ag 1 Cu 3 Au 9 clusters are identified as more stable than their neighboring clusters, based on the excess energy and second‐order difference energy. Regarding the electronic properties, all ternary clusters exhibit reduced HOMO–LUMO gaps compared to pure clusters. Notably, the Ag 1 Cu 7 Au 5 cluster shows the highest ionization potential and the lowest electron affinity, whereas the Ag 8 Cu 3 Au 2 cluster displays the opposite trend. Regarding the optical properties, most 13‐atom Au‐Ag‐Cu ternary clusters demonstrate a red shift relative to pure clusters, with absorption spanning from the visible to the near‐UV region. Of the Au‐Ag‐Cu ternary clusters investigated here, the Ag 6 Cu 1 Au 6 cluster exhibits the strongest absorption peak at 314.70 nm, whereas the Ag 5 Cu 3 Au 5 cluster shows the strongest absorption in the visible region. This study identified significant factors affecting the stability of Au‐Ag‐Cu ternary clusters, providing direction for future research on the stability of more complex ternary clusters. Investigation of optical properties offers a theoretical basis for the prospects of Au‐Ag‐Cu ternary clusters as optoelectronic materials.