Comparison of the bonding in Au8 and Cu8:: A density functional theory study -: art. no. 073408

Octamer isomers of gold are investigated within the density functional theory and compared with results for copper. The stable isomer for gold is two dimensional, whereas it is three dimensional for copper. For both elements, an analysis of the electronic structure reveals a substantial hybridization between (n - 1)d and ns orbitals. The preference of planar configurations for Au is traced to a sizable d-d overlap and d-electron delocalization. The calculated energetic ordering of Au-8 isomers is, furthermore, shown to strongly depend on two computational approximations: the choice of exchange-correlation functional and treatment of semicore polarization.