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Base-Centered Orthorhombic La₂CuO₄ CuLa₂O₄

Orthorhombic · space group Cmce (No. 64) · Pearson oC28

Symmetry elements and Wyckoff positions (interactive)

Base-Centered Orthorhombic La₂CuO₄ in Cmce

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

Unit cell

Lattice constants
a = 5.357 Å, b = 13.143 Å, c = 5.406 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
380.6 ų
Atoms in the conventional cell
28 (Cu 4, O 16, La 8)
Formula units Z
4
Pearson symbol
oC28 — orthorhombic, base-centred lattice, 28 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Cu1Cu4a40.00000.00000.0000
O3O8e80.25000.00720.2500
La2La8f80.00000.63850.9933
O4O8f80.00000.81630.0341

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 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

AB2C4_oC28_64_a_f_ef-003: 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 64, then the Wyckoff letters occupied by each element in turn (Cu: 4a; O: 8e; La: 8f; O: 8f). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

La₂NiO₄, Nd₂CeO₄, Sc₂(La, Sr)O₄ <!--beginning with an

Note: BCO La₂CuO₄.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2C4_oC28_64_a_f_ef-003 (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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