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Hg₃S₂I₂

Orthorhombic · space group Imma (No. 74) · Pearson oI56

Symmetry elements and Wyckoff positions (interactive)

Hg₃S₂I₂ in Imma

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

Unit cell

Lattice constants
a = 18.703 Å, b = 9.799 Å, c = 9.462 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
1734.2 ų
Atoms in the conventional cell
56 (I 16, Hg 24, S 16)
Formula units Z
8
Pearson symbol
oI56 — orthorhombic, body-centred lattice, 56 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
I4I4e40.00000.25000.9858
I5I4e40.00000.25000.5086
Hg1Hg8f80.85060.00000.0000
Hg3Hg8h80.00000.98570.2525
Hg2Hg8i80.86300.25000.2906
I6I8i80.75190.25000.5195
S7S16j160.87220.00730.2524

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 56 atoms drawn above are these sites multiplied by all 16 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

A3B2C2_oI56_74_fhi_2ei_j-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oI56, then the space-group number 74, then the Wyckoff letters occupied by each element in turn (I: 4e; I: 4e; Hg: 8f; Hg: 8h; Hg: 8i; I: 8i; S: 16j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Hg₃Se₂I₂ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3B2C2_oI56_74_fhi_2ei_j-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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