High stability of the goldalloy fullerenes:A density functional theory investigation of M₁₂@Au₂₀ (M=Na, Al, Ag, Sc, Y, La, Lu, and Au) clusters

Discovering highly stable metal fullerenes such as the celebrated C₆₀ is interesting in cluster science as they have potential applications as building blocks in new nanostructures. We here investigated the structural and electronic properties of the fullerenes M₁₂@Au₂₀ (M=Na, Al, Ag, Sc, Y, La, Lu, and Au), using a first-principles investigation with the density functional theory. It is found that these compound clusters possess a similar cage structure to the icosahedral Au₃₂ fullerene. La₁₂@Au₂₀ is found to be particularly stable among these clusters. The binding energy of La₁₂@Au₂₀ is 3.43 eV per atom, 1.05 eV larger than that in Au₃₂. The highest occupied molecular orbital--lowest unoccupied molecular orbital (HOMO--LUMO) gap of La₁₂@Au₂₀ is only 0.31 eV, suggesting that it should be relatively chemically reactive.