Clusters bonding theory

How is this electronic feature of the metal atom incorporated into cluster bonding models We need a little more cluster bonding theory to answer this question as well... 

It is difficult to predict with the ways in which cluster bonding theory will develop in the future, since the theoretical chemist is dependent on synthetic chemists, spectroscop-ists and crystallographers for raw data. As novel types of clusters are characterised, our ideas concerning the electronic structures of cluster molecules, have to be modified. The... 

The Characterization and Properties of Small Metal Particles. Y. Takasu and A. M. Bradshaw, Surf. Defect. Prop. Solids p. 401 1978). 2. Cluster Model Theory. R. P. Messmer, in "The Nature of the Chemisorption Bond G. Ertl and T. Rhodin, eds. North-Holland Publ., Amsterdam, 1978. 3. Clusters and Surfaces. E. L. Muetterties, T. N. Rhodin, E. Band, C. F. Brucker, and W. R. Pretzer, Cornell National Science Center, Ithaca, New York, 1978. 4. Determination of the Properties of Single Atom and Multiple Atom Clusters. J. F. Hamilton, in "Chemical Experimentation Under Extreme Conditions (B. W. Rossiter, ed.) (Series, "Physical Methods of Organic Chemistry ), Wiley (Interscience), New York (1978). 

R. Ludwig, O. Reis, R. Winter, F. Weinhold, and T. C. Farrar. Quantum cluster equilibrium theory of liquids temperature dependence of hydrogen bonding in liquid A-methylacetamide studied by IR spectra. J. Phys. Chem. B 102, 9312-18 (1998). 

P. Borowski, J. Jaroniec, T. Janowski, and K. Wolinski. Quantum cluster equilibrium theory treatment of hydrogen-bonded liquids water, methanol and ethanol. Mol. Phys. 101, 1413-21 (2003). [This paper suggests the need for more accurate treatment of free cluster rotations that become hindered librations at normal liquid densities, thus reducing the populations of larger clusters.]... 

From this simple beginning, a large body of less rigorous but useful bonding theory has been elaborated. It can be shown that for all boron clusters of the B H type which are closed polyhedra (Fig. 8.15), with n from 5 to 12, the optimum number of bonding electron pairs within the cluster is n + 1, just as we have found for B6Hg . Therefore, all of these closo boron clusters are predicted to occur as dianions, and all of them do. 

---