Structure Evolution of Transition Metal-doped Gold Clusters M@Au<sub>12</sub> (M = 3d–5d): Across the Periodic Table
Qiuying Du, Xue Wu, Pengju Wang, Di Wu, Linwei Sai, R. Bruce King, Sung Jin Park, Jijun Zhao
Abstract
The comprehensive genetic algorithm (CGA) incorporated with density functional theory (DFT) calculations were used for a global search of the potential energy surfaces of M@Au12 (M = 3d–5d) clusters. The feasibility of the revTPSS functional was confirmed by comparison between experimental and calculated data such as bond lengths and vibrational frequencies of transition metal dimers. We found the ground state structures of Mo/W@Au12 clusters to be the perfect icosahedron cage. The V/Nb/Ta/Tc/Re@Au12 clusters were found to have the distorted icosahedron cages owing to Jahn–Teller effects. The lowest energy structures of Sc/Ti/Cr/Mn/Fe/Co/Ru/Rh/Ir@Au12 have the perfect or distorted magnetic cuboctahedron cages, which can be explained by a 14-electron rule in a cuboctahedral ligand field (M2+@Au122–). Y/Zr/La/Hf@Au12 clusters have the half-cage ground states, while Ni/Cu/Zn/Pt/Ag/Cd/Pd/Au/HgAu12 clusters have oblate ground states. The scalar relativistic X2C method combined with revTPSS/TZP were used to calculate the energy difference between the magnetic cuboctahedron ground state and the icosahedron isomers of Cr@Au12 using energy decomposition analysis-natural orbitals for chemical valence. The magnetic M2+@Au122– model was found to significantly enhance the d orbital interactions of transition metal atoms and reduce Pauli repulsion, resulting in magnetic cuboctahedra as the more stable structures.