Skip to content

Crystal Lab › Prototype structures › Orthorhombic

High-Temperature AlPO₄-25 AlO₄P

Orthorhombic · space group Cmme (No. 67) · Pearson oC72

Symmetry elements and Wyckoff positions (interactive)

High-Temperature AlPO₄-25 in Cmme

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

Unit cell

Lattice constants
a = 15.203 Å, b = 8.408 Å, c = 9.449 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
1207.9 ų
Atoms in the conventional cell
72 (O 48, Al 24)
Formula units Z
24
Pearson symbol
oC72 — orthorhombic, base-centred lattice, 72 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
O3O4c40.00000.00000.0000
O4O4g40.00000.25000.8924
O5O8i80.12250.00000.5000
O6O8l80.25000.00000.6983
Al1Al8m80.00000.06520.8434
O7O8n80.65290.25000.6692
Al2Al16o160.15180.94870.6465
O8O16o160.08750.99970.7683

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 72 atoms drawn above are these sites multiplied by all 16 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

AB2_oC72_67_mo_cgilno-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC72, then the space-group number 67, then the Wyckoff letters occupied by each element in turn (O: 4c; O: 4g; O: 8i; O: 8l; Al: 8m; O: 8n; Al: 16o; O: 16o). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2_oC72_67_mo_cgilno-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.

← RbPaF₆ (V)  ·  Space group Cmme (7 prototypes)  ·  All prototypes  ·  HoCuP₂ →