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Crystal Lab › Prototype structures › Tetragonal

Phase II K₂SnCl₆ Cl₆K₂Sn

Tetragonal · space group P4/mnc (No. 128) · Pearson tP18

Symmetry elements and Wyckoff positions (interactive)

Phase II K₂SnCl₆ in P4/mnc

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

Unit cell

Lattice constants
a = 7.058 Å, b = 7.058 Å, c = 9.978 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
497.0 ų
Atoms in the conventional cell
18 (Sn 2, K 4, Cl 12)
Formula units Z
2
Pearson symbol
tP18 — tetragonal, primitive lattice, 18 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Sn4Sn2a20.00000.00000.0000
K3K4d40.00000.50000.2500
Cl1Cl4e40.00000.00000.2523
Cl2Cl8h80.22170.25110.0000

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 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

A6B2C_tP18_128_eh_d_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP18, then the space-group number 128, then the Wyckoff letters occupied by each element in turn (Sn: 2a; K: 4d; Cl: 4e; Cl: 8h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: Phase II.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A6B2C_tP18_128_eh_d_a-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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