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Mercury (II) Azide [Hg(N₃)₂]

Orthorhombic · space group Pca21 (No. 29) · Pearson oP28 · mineral: Mercury (II) Azide

Symmetry elements and Wyckoff positions (interactive)

Mercury (II) Azide [Hg(N₃)₂] in Pca21

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

Unit cell

Lattice constants
a = 10.632 Å, b = 6.264 Å, c = 6.323 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
421.1 ų
Atoms in the conventional cell
28 (Hg 4, N 24)
Formula units Z
4
Pearson symbol
oP28 — orthorhombic, primitive lattice, 28 atoms per conventional cell
Symmetry operations
4 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Hg1Hg4a40.03180.23880.2500
N2N4a40.08200.95700.1060
N3N4a40.18800.89300.1210
N4N4a40.28400.82000.1120
N5N4a40.96200.52900.3900
N6N4a40.88300.60900.2800
N7N4a40.80700.70000.1720

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 28 atoms drawn above are these sites multiplied by all 4 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

AB6_oP28_29_a_6a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP28, then the space-group number 29, then the Wyckoff letters occupied by each element in turn (Hg: 4a; N: 4a; N: 4a; N: 4a; N: 4a; N: 4a; N: 4a). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: Mercury (II) Azide.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB6_oP28_29_a_6a-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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