How many S2 do surround on each S2 in the zinc blende and in

How many S^2- do surround on each S^2- in the zinc blende and in wurtzite, respectively, if the oppositely charged ions are “ignored”? How many Zn2⁺ do surround on each Zn²⁺ in both cases?

Li ₂O has the antifluorite structure, a = 4.611 Å. Calculate the (a) Li-O distance; (b) O-O distance; (c), Li-Li distance; (d) are the oxide ions in contact? Why? (r o = 1.26Å)

Solution

6 S^2- surrounds S^2- in each structure in zinc blende as well as wurtzite.

3 Zn²⁺ surrounds  Zn²⁺ in zinc blende while 9  Zn²⁺ surrounds  Zn²⁺ in wurtzite.