Question

The structure of a binary solid substances like zinc blende. B ions from the lattice. A ions fulfill 25% of the tetrahedral holes determine the formula of the solid substance.

Solution

Let no. of unit cells = n.Then , no of Tetrahedral voids = 2n . 25% ot this = 2n/4 = n/2. So the required formula is An/2Bn or AB2 .

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