2  Solid state structure

2.1 Bloch’s theorem

2.2 Reciprocal space

2.3 Symmetry

2.3.1 Point groups

2.3.2 Space groups

2.4 Scattering

2.4.1 Structure factor

2.5 Reading

The 30th Feynman Lecture on Physics is a succinct introduction to periodicity and structure. https://www.feynmanlectures.caltech.edu/II_30.html