1 In Nickeline and Wurtzite the colored atoms took up space

1. In Nickeline and Wurtzite, the colored atoms took up space in “holes” between the clear atoms. What type of hole was filled in Nickeline? In Wurtzite?  

2. Was every hole of that type filled in each of those structures, or were there some left empty? If so, how many (by a fraction of the total) were empty?

Solution

1:- In the Nickeline octahedral holes are filled while in wurtzite tetrahedral holes are filled.

2:- the structure of nickeline distorted hcp , cations Ni²⁺ will take place all the octahedral sites, there is one octahedral hole for each hcp lattice so the stiochiometry is maintained(100% occupied).

The structure of wurtzite is hcp , Zn²⁺ cation occupy half the tetrahedral hole. There are two tetrahedral hole for each atom in hcp structure, So the stoichiometry of the compound show that only half of them are occupied (50% empty). So that there are same number of cation and anions.