Skip to content

Crystal Lab › Prototype structures › Cubic

Ca₃Al₂(OH)₁₂ (J2₃)

Cubic · space group Ia-3d (No. 230) · Pearson cI232 · Strukturbericht J23

Symmetry elements and Wyckoff positions (interactive)

Ca₃Al₂(OH)₁₂ (J2₃) in Ia-3d

Setting
Loading the group…
x = 0.10, y = 0.17, z = 0.08

Unit cell

Lattice constants
a = 12.575 Å, b = 12.575 Å, c = 12.575 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
1988.5 ų
Atoms in the conventional cell
232 (Al 16, Ca 24, H 96, O 96)
Formula units Z
8
Pearson symbol
cI232 — cubic, body-centred lattice, 232 atoms per conventional cell
Symmetry operations
96 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Al1Al16a160.00000.00000.0000
Ca2Ca24c240.12500.00000.2500
H3H96h960.90900.05400.1630
O4O96h960.97180.05310.1396

The multiplicity and the Wyckoff letter say how many copies of the site the group makes in one cell and on which kind of symmetry element the site sits; the 232 atoms drawn above are these sites multiplied by all 96 operations. Press Wyckoff under Colour to see the sites, and tick a symmetry element on the left to see which atoms lie on it.

How to read the label

A2B3C12D12_cI232_230_a_c_h_h-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cI232, then the space-group number 230, then the Wyckoff letters occupied by each element in turn (Al: 16a; Ca: 24c; H: 96h; O: 96h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: J2₃.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B3C12D12_cI232_230_a_c_h_h-001 (M. J. Mehl et al., Comput. Mater. Sci. 136, S1 (2017); D. Hicks et al., ibid. 161, S1 (2019) and 199, 110450 (2021); S. Eckert et al., ibid. 240, 112988 (2024)). Symmetry elements, Wyckoff assignment and the diagram are computed on this page from the group operations.

 ·  Space group Ia-3d (8 prototypes)  ·  All prototypes  ·  Garnet [S1₄, Co₃Al₂(SiO₄)₃] →