Electronic structure silicon clusters

Silicon cluster reactions are an example of a newly emerging field of research which is very amenable to study with electronic structure methods. This exercise will examine the potential surface for silicon cation reacting with silane (SiH4). Such reactions are central to the growth of large silicon clusters, which occurs by sequential additions of -SiHj ... 

Atomic and Electronic Structures of Boron Clusters in Crystalline Silicon The Case of X( B6 and X B12, X=H-Br... 

Raghavachari, K. (1986). Theoretical study of small silicon clusters Equilibrium geometries and electronic structures of Si (n = 2-7, 10). J. Chem. Phys. 84, 5672-86. 

As discussed earlier, it is now possible to make and study deposits of monosized, highly dispersed, transition metal clusters.(S) In this section we summarize results from the first measurements of the valence and core level photoemission spectra of mass selected, monodispersed platinum clusters. The samples are prepared by depositing single size clusters either on amorphous carbon or upon the natural silica layer of a silicon wafer. We allow the deposition to proceed until about 10 per cent of the surface in a 0.25 cm2 area is covered. For samples consisting of the platinum atom through the six atom duster, we have measured the evolution of the individual valence band electronic structure and the Pt 4f... 

The electronic structure of microcrystalline silicon of one-dimensional (1-D), 2-D, and 3-D clusters were calculated using the Discrete-Variational (DV)-Xa Molecular-Orbital method. The calculated results are discussed with respect to the effect of the size and the number of dimensions on the energy levels of molecular orbitals. The energy-gap (Eg) between the highest-occupied molecular orbital (HOMO) and the lowest-unoccupied molecular orbital (LUMO) decreases with the increase of cluster size amd the number of dimensions. It is found that including silicon 3d orbitals as basis sets decreases the Eg value. The results show that the components of silicon 3d orbitals in the unoccupied levels near LUMO are over 50 per cent. The calculated results predict that the Eg value will be close to the band gap of crystalline silicon when a 3-D cluster contadns more than 1000 silicon atoms with a diameter of 4nm. 

Crystalline silicon is well known as one of the most useful semiconductors for electronic devices. Many theoretical calculations on the electronic structure of crystalline silicon have been done by the band structure calculation or the cluster method. 

We used the Discrete Variational (DV)-A a Moleculax-Orbital (MO) metho to calculate the electronic structures of 1-D, 2-D, and 3-D silicon clusters and studied the effect of size and number of dimensions on their Eg values. 

The most stable clusters of tin, as well as of the rest of the elements in this group except carbon, are, by far, the nine-atom clusters. As mentioned above, Sng was the first deltahedral cluster to be structurally characterized. While Geg was added very soon after, nine-atom clusters of lead and silicon were found respectively 20 and 30 years later. ° Thus, the following discussion of geometry, charges, cluster-bonding, and electronic structure is valid not only for tin clusters, but also for those of silicon, germanium, and lead. 

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