Question

Calculate the following:
a. Number of `Zns` units in a unit cell of zine blende.
b. Number of `CaF_(2)` unit cell of `CaF_(2)`.

Answer 1

a. `Zn^(2+) = 4` (within the body),
`S^(2-) = 8 xx (1)/(8)+6xx(1)/(2) = 4`
b. `Ca^(2+) = underset(("corner"))(8 xx (1)/(8))+underset(("face centres"))(6xx(1)/(2)) = 4`
`F^(Θ) = 8` (within the body)