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Crystal Lab › Prototype structures › Orthorhombic

AlPO₄-8 AlO₄P

Orthorhombic · space group Cmcm (No. 63) · Pearson oC216

Symmetry elements and Wyckoff positions (interactive)

AlPO₄-8 in Cmcm

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

Unit cell

Lattice constants
a = 33.290 Å, b = 14.704 Å, c = 8.386 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
4104.9 ų
Atoms in the conventional cell
216 (O 144, Al 72)
Formula units Z
72
Pearson symbol
oC216 — orthorhombic, base-centred lattice, 216 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
O6O4a40.00000.00000.0000
O7O4c40.00000.90420.2500
O8O8e80.67250.00000.0000
O9O8e80.08760.00000.0000
O10O8e80.78520.00000.0000
Al1Al8f80.00000.09580.9356
O11O8g80.18620.39990.2500
O12O8g80.08190.10300.2500
O13O8g80.22680.09840.2500
O14O8g80.34360.27990.2500
Al2Al16h160.18620.39990.0647
Al3Al16h160.08190.10300.0637
Al4Al16h160.27230.40160.9351
Al5Al16h160.15640.22010.9352
O15O16h160.04040.14370.0000
O16O16h160.22970.37710.0000
O17O16h160.15630.32270.0000
O18O16h160.19540.17220.0000
O19O16h160.11760.16530.0000

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 216 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_oC216_63_f4h_ac3e4g5h-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC216, then the space-group number 63, then the Wyckoff letters occupied by each element in turn (O: 4a; O: 4c; O: 8e; O: 8e; O: 8e; Al: 8f; O: 8g; O: 8g; O: 8g; O: 8g; Al: 16h; Al: 16h; Al: 16h; Al: 16h; O: 16h; O: 16h; O: 16h; O: 16h; O: 16h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: AlPO₄-8.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2_oC216_63_f4h_ac3e4g5h-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.

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