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Crystal Lab › Prototype structures › Hexagonal

Ce₂Ni₇

Hexagonal · space group P63/mmc (No. 194) · Pearson hP36

Symmetry elements and Wyckoff positions (interactive)

Ce₂Ni₇ in P63/mmc

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

Unit cell

Lattice constants
a = 4.980 Å, b = 4.980 Å, c = 24.520 Å; α = 90.00°, β = 90.00°, γ = 120.00°
Cell volume
526.6 ų
Atoms in the conventional cell
36 (Ni 28, Ce 8)
Formula units Z
4
Pearson symbol
hP36 — hexagonal / trigonal, primitive lattice, 36 atoms per conventional cell
Symmetry operations
24 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Ni1Ni2a20.00000.00000.0000
Ni2Ni4e40.00000.00000.1670
Ce3Ce4f40.33330.66670.5302
Ce4Ce4f40.33330.66670.6747
Ni5Ni4f40.33330.66670.1666
Ni6Ni6h60.16490.32980.2500
Ni7Ni12k120.83380.66760.9146

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 36 atoms drawn above are these sites multiplied by all 24 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

A2B7_hP36_194_2f_aefhk-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP36, then the space-group number 194, then the Wyckoff letters occupied by each element in turn (Ni: 2a; Ni: 4e; Ce: 4f; Ce: 4f; Ni: 4f; Ni: 6h; Ni: 12k). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ce₂Co₇, Dy₂Ni₇, Er₂Ni₇, Eu₂Pt₇, Gd₂Co₇, Gd₂Ni₇, La₂Co₇, La₂Ir₇, La₂Ni₇, La₂Rh₇, Nd₂Co₇, Nd₂Ni₇, Pr₂Co₇, Pr₂Ni₇, Sc₂Ni₇, Sm₂Co₇, Sm₂Ni₇, Tb₂Ni₇, Th₂Co₇, Th₂Fe₇, Th₂Ni₇, Y₂Ni₇ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B7_hP36_194_2f_aefhk-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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