Skip to content

Crystal Lab › Prototype structures › Orthorhombic

IrSe₂

Orthorhombic · space group Pnma (No. 62) · Pearson oP24

Symmetry elements and Wyckoff positions (interactive)

IrSe₂ in Pnma

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

Unit cell

Lattice constants
a = 20.955 Å, b = 3.743 Å, c = 5.938 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
465.7 ų
Atoms in the conventional cell
24 (Ir 8, Se 16)
Formula units Z
8
Pearson symbol
oP24 — orthorhombic, primitive lattice, 24 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ir1Ir4c40.07620.25000.0700
Ir2Ir4c40.30500.25000.0581
Se3Se4c40.36080.25000.4254
Se4Se4c40.62200.25000.0461
Se5Se4c40.76260.25000.8199
Se6Se4c40.99110.25000.7725

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

AB2_oP24_62_2c_4c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP24, then the space-group number 62, then the Wyckoff letters occupied by each element in turn (Ir: 4c; Ir: 4c; Se: 4c; Se: 4c; Se: 4c; Se: 4c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

IrS₂ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2_oP24_62_2c_4c-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.

← Chalcostibite (CuSbS₂, F5₆)  ·  Space group Pnma (113 prototypes)  ·  All prototypes  ·  SrCuYSe₃ (Eu₂CuS₃) →