Covalent compounds giant lattices

CoSii, and VaSi, and some have been known for more than 100 years (59). Other more complex types containing three or more components, such as MnsSiaC, are also known. They all form three-dimensional giant lattices, often of an unusual and complicated kind, and can best be considered as intermediate in nature between alloy systems and macromolecular covalent compounds. The study of silicides has considerably intensified in the past decade, since it has been found that some show promise as electronic materials, while at the same time they are strong and highly resistant to chemical attack. A number of books and general reviews may be noted (18, 257, 318, 340, 360, 423). 

When A and B are both electronegative they form covalent compounds. These may consist of individual molecules (02, H20, etc.) or of giant covalent lattices (polymeric solids) with a... 

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