Structure of cubic zinc sulfide

The structure of cubic zinc sulfide (zinc blende, sphalerite) may be described as a ccp of S atoms, in which half of the tetrahedral sites are filled with Zn atoms the arrangement of the filled sites is such that the coordination numbers of S and Zn are both four, as shown in Fig. 10.1.7. The crystal belongs to space group 7 2 — / 43m. Note that the roles of the Zn and S atoms can be interchanged by a simple translation of the origin. 

Many binary compounds adopt the cubic zinc sulfide structure. Some of these compounds and their unit-cell parameter a values are listed in Table 10.1.6. 

The ternary iodide Cu2Hgl4, a structural analog of Ag2Hgl4with very similar properties, exists as brown tetragonal crystals at room temperature. Its high-temperature crystalline form (transition temperature is 80°C) belongs to the cubic system and exhibits the red color. 

Many ternary, quaternary, and multicomponent metal sulfides also exhibit tetrahedral coordination of atoms and possess structures similar to that of cubic 

Structure of Ag2Hgl4 [large white circle, I small black circle, (Hg2+) small 2 

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