Metalloid cluster stability

In multi-component liquids, stabilization of the liquid is revealed by the formation of eutectics where the freezing temperature is suppressed. In such liquids, the atomic species (say A and B) are not distributed at random. There are more associated AB pairs (or other clusters) than expected for a random distribution. As a result in binary metal-metalloid alloys, such as Fe-B, the low melting-point eutectics occur at preferential compositions. The most common of these is at about 17 at. % B, or an atom ratio of one B for five Fe atoms (Gilman, 1978). This suggests that clusters of metal atoms surrounding metalloid atoms form (trigonal bipyramids). These probably share corners, edges, and faces. 

In summary, the bonding situation found in the deltahedral stmctures of bare Zintl ions, which follow Wade s mles, changes smoothly to that observed in ligand-stabilized metalloid and heteroatomic clusters. Therefore, they can be considered as a subclass of intermetalloid clusters. The accessibility of larger intermetalloid... 

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