Skip to content

Crystal Lab › Prototype structures › Trigonal

Hexagonal BiI₃

Trigonal · space group P-31m (No. 162) · Pearson hP8

Symmetry elements and Wyckoff positions (interactive)

Hexagonal BiI₃ in P-31m

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

Unit cell

Lattice constants
a = 7.500 Å, b = 7.500 Å, c = 6.900 Å; α = 90.00°, β = 90.00°, γ = 120.00°
Cell volume
336.1 ų
Atoms in the conventional cell
8 (Bi 2, I 6)
Formula units Z
2
Pearson symbol
hP8 — hexagonal / trigonal, primitive lattice, 8 atoms per conventional cell
Symmetry operations
12 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Bi1Bi2c20.33330.66670.0000
I2I6k60.66670.00000.2580

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 8 atoms drawn above are these sites multiplied by all 12 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

AB3_hP8_162_c_k-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP8, then the space-group number 162, then the Wyckoff letters occupied by each element in turn (Bi: 2c; I: 6k). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

TiCl₃ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3_hP8_162_c_k-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.

← β-V₂N (L'3₂)  ·  Space group P-31m (5 prototypes)  ·  All prototypes