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Ca₃Al₂O₆

Cubic · space group Pa-3 (No. 205) · Pearson cP264

Symmetry elements and Wyckoff positions (interactive)

Ca₃Al₂O₆ in Pa-3

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

Unit cell

Lattice constants
a = 15.263 Å, b = 15.263 Å, c = 15.263 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
3555.7 ų
Atoms in the conventional cell
264 (Ca 72, Al 48, O 144)
Formula units Z
24
Pearson symbol
cP264 — cubic, primitive lattice, 264 atoms per conventional cell
Symmetry operations
24 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ca3Ca4a40.00000.00000.0000
Ca4Ca4b40.50000.50000.5000
Ca5Ca8c80.25610.25610.2561
Ca6Ca8c80.37500.37500.3750
Al1Al24d240.25260.01330.0197
Al2Al24d240.24440.23350.0046
Ca7Ca24d240.13860.37630.1272
Ca8Ca24d240.38000.38380.1209
O10O24d240.48350.13150.2536
O11O24d240.26640.28410.1049
O12O24d240.23500.40470.2921
O13O24d240.34910.96150.8926
O14O24d240.15090.98960.9758
O9O24d240.27770.12410.0103

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 264 atoms drawn above are these sites multiplied by all 24 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

A2B3C6_cP264_205_2d_ab2c2d_6d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cP264, then the space-group number 205, then the Wyckoff letters occupied by each element in turn (Ca: 4a; Ca: 4b; Ca: 8c; Ca: 8c; Al: 24d; Al: 24d; Ca: 24d; Ca: 24d; O: 24d; O: 24d; O: 24d; O: 24d; O: 24d; O: 24d). 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 A2B3C6_cP264_205_2d_ab2c2d_6d-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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