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Crystal Lab › Prototype structures › Tetragonal

α'-V₈O OV₈

Tetragonal · space group P42/mnm (No. 136) · Pearson tP18

Symmetry elements and Wyckoff positions (interactive)

α'-V₈O in P42/mnm

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

Unit cell

Lattice constants
a = 8.754 Å, b = 8.754 Å, c = 2.996 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
229.6 ų
Atoms in the conventional cell
18 (O 2, V 16)
Formula units Z
2
Pearson symbol
tP18 — tetragonal, primitive lattice, 18 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
O1O2a20.00000.00000.0000
V2V4f40.12500.12500.0000
V3V4f40.37500.37500.0000
V4V8i80.62500.12500.0000

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 18 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

AB8_tP18_136_a_2fi-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP18, then the space-group number 136, then the Wyckoff letters occupied by each element in turn (O: 2a; V: 4f; V: 4f; V: 8i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: α'-V₈O.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB8_tP18_136_a_2fi-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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