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Crystal Lab › Prototype structures › Tetragonal

CePt₂In₇

Tetragonal · space group I4/mmm (No. 139) · Pearson tI20

Symmetry elements and Wyckoff positions (interactive)

CePt₂In₇ in I4/mmm

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

Unit cell

Lattice constants
a = 4.609 Å, b = 4.609 Å, c = 21.627 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
459.5 ų
Atoms in the conventional cell
20 (Ce 2, In 14, Pt 4)
Formula units Z
2
Pearson symbol
tI20 — tetragonal, body-centred lattice, 20 atoms per conventional cell
Symmetry operations
32 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ce1Ce2a20.00000.00000.0000
In2In2b20.00000.00000.5000
In3In4d40.00000.50000.2500
Pt5Pt4e40.00000.00000.3258
In4In8g80.00000.50000.1082

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 32 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

AB7C2_tI20_139_a_bdg_e-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI20, then the space-group number 139, then the Wyckoff letters occupied by each element in turn (Ce: 2a; In: 2b; In: 4d; Pt: 4e; In: 8g). 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 AB7C2_tI20_139_a_bdg_e-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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