Review Questions for Lecture 8:  Internal Symmetry

1. To build 3D crystals, we need an additional  operation to move
motifs to build crystals. What is this operation?

2. When combined with rotational symmetry elements, two additional
symmetry elements are created. What are these?

3. 230 unique combinations of rotational plus translational symmetry result in
what?

4. Differentiate between motif and lattice.

5. What is a unit cell?