Probing the structures and electronic properties of anionic and neutral BiAun−1,0 (n = 2–20) clusters: a pyramid-like BiAu13 cluster

Abstract

The geometric structures and electronic properties of bismuth-doped gold clusters, BiAu_n^−1,0 (n = 2–20), are studied via a combination of the Crystal structure AnaLYsis by Particle Swarm Optimization structure prediction software and the density functional theory approach. Three-dimensional geometries are found to be dominant in the investigated clusters, whereas two planar isomers are observed for BiAu₂^−1,0. The BiAu₁₃ cluster possesses a “pyramid-shaped” global minimum structure. The photoelectron spectra of BiAu_n⁻¹ clusters are simulated and the results of the simulation are compared with the experimental spectra (BiAu⁻¹). It is found through stability analysis that the second-order energy difference and the HOMO–LUMO energy gap of BiAu_n clusters exhibit an odd–even trend, while those of BiAu_n⁻¹ clusters exhibit the opposite trend. The chemical bonding analysis shows an improved stability of BiAu₁₃ due to the strong spd interaction between the atomic orbitals of Bi and Au atoms.