First Brillouin zone for cubic lattices — drag to rotate
The first Brillouin zone is the Wigner-Seitz cell of the reciprocal lattice — the region of k-space closer to Γ=(0,0,0) than to any other reciprocal lattice point. SC → cube. BCC real space → FCC reciprocal → truncated octahedron BZ. FCC real space → BCC reciprocal → truncated octahedron BZ. High-symmetry points label band structure calculations.