Structure, stability, and electronic property of carbon-doped gold clusters AunC− (n = 1–10): A density functional theory study

The equilibrium geometric structures, relative stabilities, and electronic properties of AunC− and Aun+1− (n = 1–10) clusters are systematically investigated using density functional theory with hyper-generalized gradient approximation. The optimized geometries show that one Au atom capped on Aun−1C− clusters is a dominant growth pattern for AunC− clusters. In contrast to Aun+1− clusters, AunC− clusters are most stable in a quasi-planar or three-dimensional structure because C doping induces the local non-planarity while the rest of the structure continues to grow in a planar mode, resulting in an overall non-2D configuration. The relative stability calculations show that the impurity C atom can significantly enhance the thermodynamic stability of pure gold clusters. Moreover, the effect of C atom on the Aun− host decreases with the increase of cluster size. The HOMO-LUMO gap curves show that the interaction of the C atom with Aun− clusters improves the chemical stability of pure gold clusters, except for Au3− and Au4− clusters. In addition, a natural population analysis shows that the charges in corresponding AunC− clusters transfer from the Aun− host to the C atom. Meanwhile, a natural electronic configuration analysis also shows that the charges mainly transfer between the 2s and 2p orbitals within the C atom