Au10 cluster was reexamined by performing both the MP2 calculations and density functional theory (DFT) calculations using several popular functionals, including the B3LYP, BPW91, B3PW91 and PW91. Six most stable isomers of the cluster have been located, and their relative stability, electronic property, and the reactivity towards an oxygen molecule have been studied in details. Our calculated results show that the relative stability of the isomers depends on the level of theory used: in the framework of DFT, Au10 trends to form planar structures, while the MP2 calculations show that the three-dimensional isomers are energetically more favorable. Based on the present results, Au10 may be conjecturably a critical species of gold clusters which bridges the planar structures and three-dimensional ones.

Key words: Au cluster, geometrical structure, electronic property, DFT, MP2