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Crystal Lab › Prototype structures › Tetragonal

LuNi₂B₂C

Tetragonal · space group I4/mmm (No. 139) · Pearson tI12

Symmetry elements and Wyckoff positions (interactive)

LuNi₂B₂C in I4/mmm

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

Unit cell

Lattice constants
a = 3.464 Å, b = 3.464 Å, c = 10.631 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
127.6 ų
Atoms in the conventional cell
12 (C 2, Lu 2, Nd 4, B 4)
Formula units Z
2
Pearson symbol
tI12 — tetragonal, body-centred lattice, 12 atoms per conventional cell
Symmetry operations
32 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
C2C2a20.00000.00000.0000
Lu3Lu2b20.00000.00000.5000
Nd4Nd4d40.00000.50000.2500
B1B4e40.00000.00000.8618

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 12 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

A2BCD2_tI12_139_e_a_b_d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI12, then the space-group number 139, then the Wyckoff letters occupied by each element in turn (C: 2a; Lu: 2b; Nd: 4d; B: 4e). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

GdN₂B₂C, LaIr₂B₂C, LaN₂B₂C, LaPt₂B₂C, LaRh₂B₂C <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BCD2_tI12_139_e_a_b_d-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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