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Crystal Lab › Prototype structures › Orthorhombic

Tongbaite (Cr₃C₂, D5₁₀)

Orthorhombic · space group Pnma (No. 62) · Pearson oP20 · Strukturbericht D510 · mineral: tongbaite

Symmetry elements and Wyckoff positions (interactive)

Tongbaite (Cr₃C₂, D5₁₀) in Pnma

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

Unit cell

Lattice constants
a = 5.533 Å, b = 2.829 Å, c = 11.472 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
179.6 ų
Atoms in the conventional cell
20 (C 8, Cr 12)
Formula units Z
4
Pearson symbol
oP20 — orthorhombic, primitive lattice, 20 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
C1C4c40.10080.25000.2055
C2C4c40.24320.25000.9536
Cr3Cr4c40.01570.25000.4015
Cr4Cr4c40.18080.25000.7737
Cr5Cr4c40.86910.25000.9312

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 20 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

A2B3_oP20_62_2c_3c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP20, then the space-group number 62, then the Wyckoff letters occupied by each element in turn (C: 4c; C: 4c; Cr: 4c; Cr: 4c; Cr: 4c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Hf₃P₂, La₂S₃ <!--beginning with an

Note: D5₁₀, Tongbaite.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B3_oP20_62_2c_3c-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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