Predicting crystal structures

Question 1

How many holes are there in ccp unit cells?

Answer 1

4 octahedral and 8 tetrahedral

Question 2

how many holes are there in a hcp unit cell?

Answer 2

2 octahedral and 4 tetrahedral

Question 3

How many lattic points do hcps always have

Answer 3

two

Question 4

What is the relationship between close packed atoms and holes in crystal structures?

Answer 4

The same amount of octahedral holes and twice the amount of tetrahedral holes