Bloch Theorem & Pauli Exclusion Principle
Bloch wavefunctions describe electrons in periodic potentials: ψₖ(r) = uₖ(r)·e^(ikr)
The periodic part uₖ(r) has the same periodicity as the lattice.
Each quantum state can hold maximum 2 electrons (spin up & down).
Electrons fill energy levels from lowest to highest (Fermi-Dirac distribution).
Crystal structure parameters and calculated band structure properties.