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Metal clusters charge transfer model

The nature of bonding of the adsorbed species to the model cluster of metal surfaces can be analyzed in terms of the so-called constrained space orbital variation (CSOV) method. For halogen anions adsorbed on various silver surfaces, it has been found that Pauli repulsion, metal polarization, and charge transfer to the metal surface mainly contribute to the binding energy of the ions [104, 301]. [Pg.941]

The electronic structure and energy of an A1 cluster in metastable equilibrium with a jS-SiC (face (001)) have been modelled by Hoekstra and Kohyama (1998) using ab initio calculations. Both C- and Si-terminated faces were examined and strong bonds with A1 were found in all cases, but with a higher adhesion energy for Al/C-SiC than Al/Si-SiC. Moreover, the Al/C-SiC bond was found to be predominantly covalent (albeit with some charge transfer from A1 to C), as for the bond between Si and C in bulk SiC, while the Al/Si-SiC bond was rather metallic. These calculated results are compatible with the fact that the affinity of A1 for C (as... [Pg.279]

A systematic semiempirical study of the core-level photoemission spectra of a wide range of 3d transition-metal compounds has been carried out (Bocquet et al., 1992,1996). The values for U and A obtained from a simplified Cl cluster model analysis are demonstrated in Figure 7.2. As can be inferred from the graphs, the heavier 3d transition metal compounds shown in the figure are expected to be charge-transfer insulators, whereas the compounds of the fighter metals are generally expected to be of the Mott-Hubbard type. [Pg.293]

A more complex situation was found for Na Pb. The unusual stability of this cluster was explained by comparison with the analogous Mg compound (Albert et al. 1995) and was found to originate in a larger charge transfer to the more electronegative lead and a larger polarizability of the Pb atom. In a combined experimental and theoretical study it was shown for the clusters Na Au and Cs Au that certain properties of the bulk are qualitatively present at the level of small clusters (Heiz et al. 1995). While the Na compounds show metallic behaviour, and the electronic structure can be described by means of the jellium model, in the Cs-Au clusters an ionic bond is most prominent. [Pg.103]


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Metal transfer

Metallic charge

Metallic clusters charge transfer

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