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Crystal Lab › Prototype structures › Orthorhombic

Tb₃Sn₇

Orthorhombic · space group Cmmm (No. 65) · Pearson oC28

Symmetry elements and Wyckoff positions (interactive)

Tb₃Sn₇ in Cmmm

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

Unit cell

Lattice constants
a = 26.347 Å, b = 4.363 Å, c = 4.441 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
510.5 ų
Atoms in the conventional cell
28 (Tb 6, Sn 22)
Formula units Z
2
Pearson symbol
oC28 — orthorhombic, base-centred lattice, 28 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Tb7Tb2a20.00000.00000.0000
Sn1Sn2c20.50000.00000.5000
Sn2Sn4g40.40470.00000.0000
Sn3Sn4g40.21770.00000.0000
Sn4Sn4g40.18310.00000.0000
Sn5Sn4g40.24500.00000.0000
Sn6Sn4h40.10100.00000.5000
Tb8Tb4h40.30900.00000.5000

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

A11B3_oC28_65_c4gh_ah-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 65, then the Wyckoff letters occupied by each element in turn (Tb: 2a; Sn: 2c; Sn: 4g; Sn: 4g; Sn: 4g; Sn: 4g; Sn: 4h; Tb: 4h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Dy₃Sn₇, Gd₃Sn₇ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A11B3_oC28_65_c4gh_ah-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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