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Crystal Lab › Prototype structures › Monoclinic

Ta₂PdSe₆

Monoclinic · space group C12/m1 (No. 12) · Pearson mC18

Symmetry elements and Wyckoff positions (interactive)

Ta₂PdSe₆ in C12/m1

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

Unit cell

Lattice constants
a = 18.960 Å, b = 3.375 Å, c = 12.196 Å; α = 90.00°, β = 149.77°, γ = 90.00°
Cell volume
392.9 ų
Atoms in the conventional cell
18 (Pd 2, Se 12, Ta 4)
Formula units Z
2
Pearson symbol
mC18 — monoclinic, base-centred lattice, 18 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Pd1Pd2a20.00000.00000.0000
Se2Se4i40.23280.00000.2269
Se3Se4i40.11890.00000.7774
Se4Se4i40.09330.00000.3118
Ta5Ta4i40.39020.00000.0702

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 18 atoms drawn above are these sites multiplied by all 8 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

AB6C2_mC18_12_a_3i_i-004: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol mC18, then the space-group number 12, then the Wyckoff letters occupied by each element in turn (Pd: 2a; Se: 4i; Se: 4i; Se: 4i; Ta: 4i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Nb₂PdS₆, Nb₂PdSe₆, Ta₂PdS₆ <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB6C2_mC18_12_a_3i_i-004 (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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