Chalcogenides With the Tetrahedral Structure

Abstract

The diamond, or tetrahedral structure, is an excellent example of how a simple set of structural relationships can be used to understand the structures of a variety of compounds of increasing complexity. The elements C, Si, Ge, and Sn can form three-dimensional networks in which each atom forms four tetrahedral bonds. The diamond structure of gray tin transforms to white tin at 13.2°C. In white tin, the coordination number is six and the interbond angles are no longer all equal to 109.5°; two are enlarged to 149.5° and four are reduced to 94° (1).