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Crystal Lab › Prototype structures › Tetragonal

α-AlB₁₂

Tetragonal · space group P43212 (No. 96) · Pearson tP216

Symmetry elements and Wyckoff positions (interactive)

α-AlB₁₂ in P43212

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

Unit cell

Lattice constants
a = 10.158 Å, b = 10.158 Å, c = 14.270 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
1472.4 ų
Atoms in the conventional cell
216 (B 176, Al 40)
Formula units Z
8
Pearson symbol
tP216 — tetragonal, primitive lattice, 216 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
B6B4a40.66830.66830.0000
B7B4a40.96460.96460.0000
Al1Al8b80.30210.36880.2589
Al2Al8b80.08230.01180.3086
Al3Al8b80.31300.39320.3419
Al4Al8b80.28730.47850.1224
Al5Al8b80.30370.38310.2958
B10B8b80.95450.31190.2317
B11B8b80.95850.39390.1179
B12B8b80.97960.10910.0808
B13B8b80.96910.27400.0296
B14B8b80.10730.22310.2456
B15B8b80.10340.38950.1917
B16B8b80.12170.10340.1549
B17B8b80.12190.19200.0447
B18B8b80.11370.36280.0647
B19B8b80.20540.25960.1391
B20B8b80.31400.05790.3606
B21B8b80.38600.20720.3252
B22B8b80.20380.19680.3452
B23B8b80.46710.11740.4112
B24B8b80.45960.29330.4220
B25B8b80.18560.09330.4486
B26B8b80.27080.17820.5459
B27B8b80.34780.03960.4913
B28B8b80.43920.18930.5252
B8B8b80.87230.23940.1282
B9B8b80.96050.13590.2091

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 216 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

A5B22_tP216_96_5b_2a21b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP216, then the space-group number 96, then the Wyckoff letters occupied by each element in turn (B: 4a; B: 4a; Al: 8b; Al: 8b; Al: 8b; Al: 8b; Al: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b; B: 8b). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: α-AlB₁₂.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A5B22_tP216_96_5b_2a21b-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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