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Crystal Lab › Prototype structures › Monoclinic

Os₄Al₁₃

Monoclinic · space group C12/m1 (No. 12) · Pearson mC34

Symmetry elements and Wyckoff positions (interactive)

Os₄Al₁₃ in C12/m1

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

Unit cell

Lattice constants
a = 17.640 Å, b = 4.228 Å, c = 7.773 Å; α = 90.00°, β = 115.15°, γ = 90.00°
Cell volume
524.8 ų
Atoms in the conventional cell
34 (Al 26, Os 8)
Formula units Z
2
Pearson symbol
mC34 — monoclinic, base-centred lattice, 34 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Al1Al2a20.00000.00000.0000
Al2Al4i40.91300.00000.6320
Al3Al4i40.24300.00000.3870
Al4Al4i40.36800.00000.8380
Al5Al4i40.71000.00000.9130
Al6Al4i40.58600.00000.5680
Al7Al4i40.09100.00000.8060
Os8Os4i40.20600.00000.7085
Os9Os4i40.50810.00000.8053

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 34 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

A13B4_mC34_12_a6i_2i-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol mC34, then the space-group number 12, then the Wyckoff letters occupied by each element in turn (Al: 2a; Al: 4i; Al: 4i; Al: 4i; Al: 4i; Al: 4i; Al: 4i; Os: 4i; Os: 4i). 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 A13B4_mC34_12_a6i_2i-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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