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Sn₃P₄

Trigonal · space group R-3m (No. 166) · Pearson hR19

Symmetry elements and Wyckoff positions (interactive)

Sn₃P₄ in R-3m

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

Unit cell

Lattice constants
a = 4.429 Å, b = 4.429 Å, c = 28.361 Å; α = 90.00°, β = 90.00°, γ = 120.00°
Cell volume
481.8 ų
Atoms in the conventional cell
57 (Sn 9, P 48)
Formula units Z
3
Pearson symbol
hR19 — hexagonal / trigonal, rhombohedral lattice, 19 atoms per conventional cell
Symmetry operations
36 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Sn5Sn3a30.00000.00000.0000
P1P6c60.00000.00000.4330
P2P6c60.00000.00000.3574
Sn6Sn6c60.00000.00000.7945
P3P18h180.20430.79570.0711
P4P18h180.47180.52820.0528

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 57 atoms drawn above are these sites multiplied by all 36 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

A16B3_hR19_166_2c2h_ac-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hR19, then the space-group number 166, then the Wyckoff letters occupied by each element in turn (Sn: 3a; P: 6c; P: 6c; Sn: 6c; P: 18h; P: 18h). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A16B3_hR19_166_2c2h_ac-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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