Structural Evolution And Electronic Properties Of Au_nM~-(n=1-7) Ion Clusters

The structural,infrared spectra and electronic properties of Aun+i- and AunM- (M=Sc-Zn and n=1-9) clusters have been researched by using density functional theory at PW91PW91 level. The structural searches show that the ground state structures of Aun+i- clusters adopts a planar structure. The 3d transition metal atoms in AunM- cluster tend to occupy the most highly coordinated position. The energy of isomers with similar structure decreases as the coordinated number of M atom increases. The dopant atoms significantly change the geometry of partial host clusters. Vibrational spectra are predicted to identify their structures in the future. The most intense peak of vibrational spectrum of each AunM- clusters is associated with the Au-Ni stretching vibrations. The relative stability and chemical activity are analyzed based on the second-order energy difference, vertical detachment energy (VDE)and the energy gaps between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). It is found that Au4Sc-?Au3Ti-?Au2V-?Au2Cr-?Au3Mn-?Au2Fe-?Au2Co-?Au2Ni-?Au2Cu-?Au2Zn- clusters have very high stability. The VDE of linear structures is smaller than that of two- and three-dimensional (2D and 3D) structures.As the clusters increase,the VDE increases. The 3D Au4Sc-, 2D Au3Mn-, linear Au2Cu- with more than 2eV H-L energy gap can be regarded as a superatom.