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Crystal Lab › Prototype structures › Tetragonal

Na₂HgO₂

Tetragonal · space group I4/mmm (No. 139) · Pearson tI10

Symmetry elements and Wyckoff positions (interactive)

Na₂HgO₂ in I4/mmm

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

Unit cell

Lattice constants
a = 3.420 Å, b = 3.420 Å, c = 13.300 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
155.6 ų
Atoms in the conventional cell
10 (Hg 2, Na 4, O 4)
Formula units Z
2
Pearson symbol
tI10 — tetragonal, body-centred lattice, 10 atoms per conventional cell
Symmetry operations
32 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Hg1Hg2a20.00000.00000.0000
Na2Na4e40.00000.00000.3250
O3O4e40.00000.00000.1470

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 10 atoms drawn above are these sites multiplied by all 32 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_tI10_139_a_e_e-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI10, then the space-group number 139, then the Wyckoff letters occupied by each element in turn (Hg: 2a; Na: 4e; O: 4e). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Cs₂HgO₂, Li₂HgO₂, Rb₂HgO₂, U₂IrC₂, U₂RuC₂ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2C2_tI10_139_a_e_e-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.

← H5₉ [Autunite Ca(UO₂)₂(PO₄)₂cdot 10 frac{1}{2}H₂O] Structure ( Obsolete ): AB2C2_tI10_139_a_d_e-003  ·  Space group I4/mmm (51 prototypes)  ·  All prototypes  ·  (T') Nd₂CuO₄ →