No. 225 F m -3 m

Number

225

Hermann–Mauguin symbol

F m -3 m

Hall symbol

-F 4 2 3

Crystal system

Cubic

Operations per cell

192

General position

192l (site symmetry 1)

Wyckoff positions (standard setting)

How to read it

• Each symmetry element drawn in the cell is worked out from the group’s operations: rotation and screw axes as lines (arrow = direction; dashed = screw), mirror and glide planes as sheets (dashed outline = glide), inversion centres as dots; rotoinversion axes are dotted. Colours: 2-fold red, 3-fold green, 4-fold blue, 6-fold purple.
• The multiplicity is how many equivalent points an atom on that site generates in the conventional cell; the general position has the highest multiplicity, equal to the number of operations.
• Site symmetry is the point group that leaves that position fixed; a special position (lower multiplicity) sits on a symmetry element — press + on a row to see its atoms land on the drawn elements.

Crystal Lab structures in this group

• Face-centred cubic (ccp) (Cu) — Elemental
• Rock salt (halite) (NaCl) — AB, 6:6
• Fluorite (CaF₂) — AB₂, 8:4
• Antifluorite (Na₂O) — A₂B, 4:8
• Silver chloride (Frenkel defects) (AgCl) — AB, 6:6 (rock salt)
• MOF-5 (IRMOF-1) (Zn₄O(BDC)₃) — Metal–organic framework
• HKUST-1 (Cu-BTC) (Cu₃(BTC)₂) — Metal–organic framework
• Magnesium nickel hydride (high-temperature form) (Mg₂NiH₄) — Complex hydride
• UiO-66 (zirconium terephthalate MOF) (Zr₆O₄(OH)₄(BDC)₆) — Metal–organic framework
• Lithium bismuthide (Li₃Bi) — A₃B (BiF₃ / Li₃Bi type)
• Prussian blue (idealised) (Fe₄[Fe(CN)₆]₃) — Cyanide framework (double perovskite-like)

Prototype structures in this group (28)

H₁₀LaB₁₂U D2fCu₁₆Mg₆Si₇Cu₂SeMn₂₃Th₆ D8aBa₂MnO₆WC₆₀K₃I₄Rb₃Re₃S₄C₆Cr₂₃ D84Cl₆K₂Pt J11C₁₂Cu₃Fe₂(H₂O)_{x}N₁₂ J25Mg₆MnO₈Cu₅FeS₄Ca₇GeCr₉Fe₁₆Ni₇Co₉S₈ D89CrFe₁₈MoNi₈AlCu₂Mn L21CaF₂ C1AlF₆H₁₂N₃ J21BiF₃ D03CuF₆ZrCuPt₃ L1aBH₄KBi₂O₃ClFNa₆O₈S₂ H58ClNa B1Cu A1