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Crystal Lab › Prototype structures › Trigonal

EuIr₂P₂

Trigonal · space group P3221 (No. 154) · Pearson hP15

Symmetry elements and Wyckoff positions (interactive)

EuIr₂P₂ in P3221

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

Unit cell

Lattice constants
a = 6.671 Å, b = 6.671 Å, c = 7.055 Å; α = 90.00°, β = 90.00°, γ = 120.00°
Cell volume
271.9 ų
Atoms in the conventional cell
15 (Eu 3, Ir 6, P 6)
Formula units Z
3
Pearson symbol
hP15 — hexagonal / trigonal, primitive lattice, 15 atoms per conventional cell
Symmetry operations
6 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Eu1Eu3a30.60070.00000.6667
Ir2Ir3a30.12970.00000.6667
Ir3Ir3b30.51830.00000.1667
P4P6c60.22240.88330.9591

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 15 atoms drawn above are these sites multiplied by all 6 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

AB2C2_hP15_154_a_ab_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP15, then the space-group number 154, then the Wyckoff letters occupied by each element in turn (Eu: 3a; Ir: 3a; Ir: 3b; P: 6c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

CaIr₂P₂, SrIr₂P₂ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2C2_hP15_154_a_ab_c-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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