Au ₂₀ : A Tetrahedral Cluster

Abstract

Photoelectron spectroscopy revealed that a 20-atom gold cluster has an extremely large energy gap, which is even greater than that of C60, and an electron affinity comparable with that of C60. This observation suggests that the Au20 cluster should be highly stable and chemically inert. Using relativistic density functional calculations, we found that Au20 possesses a tetrahedral structure, which is a fragment of the face-centered cubic lattice of bulk gold with a small structural relaxation. Au20 is thus a unique molecule with atomic packing similar to that of bulk gold but with very different properties.

Hepta‐ and Octacoordinate Boron in Molecular Wheels of Eight‐ and Nine‐Atom Boron Clusters: Observation and Confirmation

“…The next calculated VDE is at 5.86 eV from HOMO-4 (1b 1 ). Although the signalto-noise ratio is poor in the high-binding-energy side of the B 8 À spectrum (Figure 1 b), we can tentatively identify a detachment feature (D) around 5.9 eV. The overall agreement between the calculated VDEs and the PES spectra of B 8 À is excellent, confirming unequivocally its heptagonal structure.…”

“…[4,5] Figure 1 shows the PES spectra of B 8 À at three photon energies and those of B 9 À at two photon energies. The 193 nm spectrum of B 8 À revealed four distinct features labeled X, A, B, C (Figure 1 b). A fifth band (D) can be tentatively identified, but the signal-to-noise ratios are poor at the high-binding-energy side.…”

“…Combining PES and computational chemistry is a powerful means to elucidate the electronic structure and chemical bonding of novel clusters. [6][7][8] We performed an extensive computational search for the global minimum structures for B 8 , B 8 À , B 8 2À , B 9 , B 9 À by using a hybrid (density functional and HartreeFock) method. We found that all five species have planar wheel structures ( Figure 2): B 8 and B 8 2À are perfect heptagons and B 9 À is a perfect octagon, whereas B 8 À and B 9 have slight in-plane distortions within the heptagonal and octagonal structures, respectively.…”

Phenyl-Coinage Metal (Ag, Au) Complexes: an Anion Photoelectron Spectroscopy and Density Functional Study

“…38 It has been shown previously that these theoretical methods are suitable for studying the coinage metal clusters. 39 …”

“…This structural assignment method has been widely used on cluster study. 4,31,39,[41][42][43][44][45][46] EA is calculated as the difference between the total energies of the neutral and anion at their respective optimized structures. The theoretical DOS spectra are shifted by setting the HOMO level of the spectra to give the negative of VDE value for the complex.…”