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Crystal Lab › Prototype structures › Monoclinic

Nb₂Se

Monoclinic · space group C12/m1 (No. 12) · Pearson mC24

Symmetry elements and Wyckoff positions (interactive)

Nb₂Se in C12/m1

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

Unit cell

Lattice constants
a = 13.992 Å, b = 3.422 Å, c = 9.283 Å; α = 90.00°, β = 91.76°, γ = 90.00°
Cell volume
444.3 ų
Atoms in the conventional cell
24 (Nb 16, Se 8)
Formula units Z
8
Pearson symbol
mC24 — monoclinic, base-centred lattice, 24 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Nb1Nb4i40.78450.00000.8749
Nb2Nb4i40.91610.00000.6012
Nb3Nb4i40.58730.00000.6509
Nb4Nb4i40.74320.00000.3772
Se5Se4i40.85900.00000.1373
Se6Se4i40.57470.00000.1843

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 24 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

A2B_mC24_12_4i_2i-004: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol mC24, then the space-group number 12, then the Wyckoff letters occupied by each element in turn (Nb: 4i; Nb: 4i; Nb: 4i; Nb: 4i; Se: 4i; Se: 4i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Hf₂Se <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B_mC24_12_4i_2i-004 (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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