3.1 The lattice
3.2 The unit cell and fractional coordinates
3.3 Fourier Space
3.4 The reciprocal lattice
3.4.1 The cell and reciprocal-cell tensors
3.5 The structure factor equation
3.6 The electron density equation
3.7 Site Occupancies
3.8 Ideal vs. real crystals
3.9 Centering and the 14 Bravais lattices
3.10 Crystallographic Symmetry Elements
3.10.1 Proper rotations
3.10.2 Improper rotations
3.10.3 Screw axes
3.10.4 Glide planes
3.11 Space groups
3.12 Systematic Extinctions
3.13 Site symmetry and the asymmetric unit
3.14 Space groups in GSAS-II
3.15 Why does GSAS-II allow non-standard space groups?
3.16 Polar space groups
3.17 For More Information