Structural types of crystals

grouped by number of nonequivalent atomic positions and their weights. An alternative entry includes

• lattices (crystals with all atoms equivalent)
• close-packed structures (metals and alloys)
• closely copacked compounds (ionic crystals)
• locally coordinated crystals (covalent, covalent-ionic, molecular crystals)

Elementary crystals

• A1 face-centered cubic
• A2 body-centered cubic
• A3 hexagonal close-packed
• A4 diamond
• A5 beta-tin
• A6 face-centered tetragonal
• A7 alpha-arsenic (also rhombohedral graphite and beta-oxygen)
• A8 grey-selenium
• A10 simple rhombohedral
• A11 α-Ga
• A14 halogens – fcc lattice of diatomic heavy-halogen molecules with in-plane secondary ppσ bonding, see I2
• A17 black P
• Aa tetragonal close-packed (body-centered tetragonal)
• Af simple hexagonal
• Ah simple cubic
• Ai simple rhombohedral

Binary compounds and elementary crystals with two nonequivalent sites

AB crystals

• A3' alpha-lanthanum
• A9 – see graphite
• B1 rock salt
• B2 cesium chloride
• B3 zincblende
• B4 wurtzite
• B8₁ nickel arsenide
• Bh tungsten carbide
• binary A7, see GeTe

AB2 crystals

• C1 fluorite
• C2 pyrite
• C3 cuprite
• C4 rutile
• C5 anatase, see TiO2 anatase
• C19
• C32 hexagonal omega

Other binary compounds with two nonequivalent sites

• D5₁ corundum, see Al2O3

Ternary compounds and other crystals with three nonequivalent atoms

• ABX2 E1₁ chalcopyrite
• ABX3 E2₁ perovskite
• AB2X4 H1₁ spinel
• ABX4 tI24 zircon and scheelite
• AB3X6 cI80 bixbyite

Other compounds

• ABCD A16 α-S
• A2B2X6Y pyrochlore
• A2BCX4 stannite (H2₆, tI16, A=4d, B=2a, C=2b, X=8i, [a,c,x(X),z(X)])