L04_A
Energy Bands in Crystals
  Reciprocal Lattice
  Bragg Relation
  Overlapping of allowed energy bands
  Wigner-Seitz Cells
  Three-Dimensional Zone Schemes
  First Brillouin Zone of the BCC Crystal Structure
  Free Electron Bonds

L04_B
Electrons in a Crystal
  Fermi Energy and Fermi Surface
  Fermi Distribution Function
  Density of States
  Population Density