No. 194 P 63/m m c

Number

194

Hermann–Mauguin symbol

P 63/m m c

Hall symbol

-P 6c 2c

Crystal system

Hexagonal

Operations per cell

24

General position

24l (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

• Hexagonal close-packed (Mg) — Elemental
• Graphite (C) — Covalent layers
• Nickel arsenide (NiAs) — AB, 6:6 (hcp)
• Molybdenite (MoS₂) — Layered AB₂, 6:3
• Ice Ih (oxygen framework) (H₂O) — Hydrogen-bonded network
• Tantalum disulfide (2H) (TaS₂) — Layered AB₂ (trigonal prismatic)

Prototype structures in this group (74)

H₁₀HfFe₁₂O₁₉PbNa₁₃Pb₅Ni₁₇Th₂Al₂₃V₄C₄Co₃W₉Pt₂Sn₃ D5bAl₂O₃ D56Ce₂Ni₇Co₂LiNaO₄B₂BaPt₃S₂SnTaO₂Si C10B₂ReCa₂O₄SiH₂Na₂O₉Si₂Zr S34(II)Be₃N₂BO₃YBa₃CoIr₂O₉Fe₃GeTe₂Cr₃SiU₂CCaO₃Ni₃Ti D024Co₃VAl₃PuB₃ReNi₃Sn D019Mg₄SrB₅W₂ D8hAl₅Co₂ D811Sn₅Ti₆Ba₆Nd₂O₁₇Ti₄Cl₉Cr₂Cs₃Al₉Mn₃Si E9cNa₉Pb₄CoNa_{0.74}O₂EuIn₂P₂MgZn₂ C14NbSe₂MgNi₂ C36CaIn₂NbS₂InNi₂ B82MoS₂ C7CoGa₃Lu₂AlN₃Ti₄BaO₃TiCeNi₃AsNa₃ D018BaLi₄BrCu₄FH₆O₆CeH₉CuFeO₂MoNiP₂AlCCr₂BaNiO₃BGdO₃BaMnO₃CoOSrBCLiCMoCuS B18LiZn₂ CkAsNi B81Fe₂N L'30BN BkLiOAsTi BiGaSeMg A3La A3'C A9CC