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Crystal Lab › Prototype structures › Orthorhombic

Al₂PbO₄

Orthorhombic · space group Ama2 (No. 40) · Pearson oC28

Symmetry elements and Wyckoff positions (interactive)

Al₂PbO₄ in Ama2

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

Unit cell

Lattice constants
a = 8.458 Å, b = 9.234 Å, c = 5.070 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
396.0 ų
Atoms in the conventional cell
28 (O 16, Pb 4, Al 8)
Formula units Z
4
Pearson symbol
oC28 — orthorhombic, base-centred lattice, 28 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
O2O4a40.00000.00000.6412
O3O4b40.25000.68490.1527
Pb5Pb4b40.25000.52990.5003
Al1Al8c80.05410.67170.0327
O4O8c80.05640.69080.6877

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 28 atoms drawn above are these sites multiplied by all 8 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

A2B4C_oC28_40_c_abc_b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC28, then the space-group number 40, then the Wyckoff letters occupied by each element in turn (O: 4a; O: 4b; Pb: 4b; Al: 8c; O: 8c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ga₂PbO₄ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B4C_oC28_40_c_abc_b-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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