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NH₄HF₂ (F5₈)

Orthorhombic · space group Pmna (No. 53) · Pearson oP16 · Strukturbericht F58

Symmetry elements and Wyckoff positions (interactive)

NH₄HF₂ (F5₈) in Pmna

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

Unit cell

Lattice constants
a = 8.426 Å, b = 3.690 Å, c = 8.180 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
254.3 ų
Atoms in the conventional cell
16 (H 4, F 8, N 4)
Formula units Z
4
Pearson symbol
oP16 — orthorhombic, primitive lattice, 16 atoms per conventional cell
Symmetry operations
8 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
H4H2a20.00000.00000.0000
H3H2b20.50000.00000.0000
F1F4e40.13700.00000.0000
NH5N4g40.25000.46000.2500
F2F4h40.00000.13100.6290

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 16 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

A2BC_oP16_53_eh_ab_g-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP16, then the space-group number 53, then the Wyckoff letters occupied by each element in turn (H: 2a; H: 2b; F: 4e; N: 4g; F: 4h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: F5₈.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC_oP16_53_eh_ab_g-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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