Answer to Question #238959 in Physical Chemistry for SID

Question

You have been introduced to terms like Bravais lattice translations and

Wycko↵ positions. Write down all such possible translations. Are they

true only for cube or are they true for all the seven crystal systems?

Explain.

Consider two FCC structures whose Wycko↵ positions are given by (a.)

(0,0,0) for one of these, and by (b.) (0,0,0), ( 1/4,1/4,1/4) for the other. At all

the possible positions, same type of atoms are decorated/placed. Can

you give examples (one each) for such structures? Draw them. How

many number of lattice points will one see in both these structures?

How many number of atoms per lattice point do you have in them?

Answer 1

3 atoms per lattice