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K₂Cu₃Ge₄O₁₂

Orthorhombic · space group Cmcm (No. 63) · Pearson oC84

Symmetry elements and Wyckoff positions (interactive)

K₂Cu₃Ge₄O₁₂ in Cmcm

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

Unit cell

Lattice constants
a = 14.079 Å, b = 5.780 Å, c = 13.892 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
1130.5 ų
Atoms in the conventional cell
84 (Cu 12, O 48, K 8, Ge 16)
Formula units Z
4
Pearson symbol
oC84 — orthorhombic, base-centred lattice, 84 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Cu1Cu4a40.00000.00000.0000
Cu2Cu8e80.79170.00000.0000
O5O8f80.00000.44840.6191
K4K8g80.16430.89200.2500
O6O8g80.13090.34290.2500
Ge3Ge16h160.38980.09520.6273
O7O16h160.39750.36910.5752
O8O16h160.30080.90720.5949

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 84 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

A3B4C2D12_oC84_63_ae_h_g_fg2h-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oC84, then the space-group number 63, then the Wyckoff letters occupied by each element in turn (Cu: 4a; Cu: 8e; O: 8f; K: 8g; O: 8g; Ge: 16h; O: 16h; O: 16h). 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 A3B4C2D12_oC84_63_ae_h_g_fg2h-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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