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Crystal Lab › Prototype structures › Orthorhombic

β-KEr₂F₇ Er₂F₇K

Orthorhombic · space group Pnma (No. 62) · Pearson oP80

Symmetry elements and Wyckoff positions (interactive)

β-KEr₂F₇ in Pnma

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

Unit cell

Lattice constants
a = 11.820 Å, b = 7.816 Å, c = 13.333 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
1231.8 ų
Atoms in the conventional cell
80 (Er 16, F 56, K 8)
Formula units Z
8
Pearson symbol
oP80 — orthorhombic, primitive lattice, 80 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Er1Er4c40.99420.25000.2580
Er2Er4c40.79040.25000.0622
F3F4c40.16160.25000.5796
F4F4c40.24310.25000.7612
F5F4c40.36470.25000.5956
F6F4c40.68760.25000.3374
F7F4c40.62360.25000.1245
F8F4c40.97550.25000.0886
K9K4c40.08390.25000.9050
K10K4c40.43430.25000.9313
Er11Er8d80.25630.02380.6635
F12F8d80.16920.91380.8008
F13F8d80.28140.51500.4978
F14F8d80.42700.00340.7330
F15F8d80.08690.92300.6223

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 80 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

A2B7C_oP80_62_2cd_6c4d_2c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP80, then the space-group number 62, then the Wyckoff letters occupied by each element in turn (Er: 4c; Er: 4c; F: 4c; F: 4c; F: 4c; F: 4c; F: 4c; F: 4c; K: 4c; K: 4c; Er: 8d; F: 8d; F: 8d; F: 8d; F: 8d). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

α-KYb₂F₇, β-KHo₂F₇ <!--beginning with an

Note: \beta-KEr₂F₇.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B7C_oP80_62_2cd_6c4d_2c-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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