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Crystal Lab › Prototype structures › Tetragonal

Sr(OH)₂(H₂O)₈

Tetragonal · space group P4/ncc (No. 130) · Pearson tP116

Symmetry elements and Wyckoff positions (interactive)

Sr(OH)₂(H₂O)₈ in P4/ncc

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

Unit cell

Lattice constants
a = 8.984 Å, b = 8.984 Å, c = 11.517 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
929.6 ų
Atoms in the conventional cell
116 (Sr 4, H 72, O 40)
Formula units Z
4
Pearson symbol
tP116 — tetragonal, primitive lattice, 116 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Sr11Sr4a40.75000.25000.2500
H1H4c40.25000.25000.4888
H2H4c40.25000.25000.2426
O7O4c40.25000.25000.4048
O8O4c40.25000.25000.1590
H3H16g160.80440.57590.1201
H4H16g160.95300.48740.1327
H5H16g160.80540.57660.8623
H6H16g160.83920.45960.9602
O9O16g160.84540.47220.1255
O10O16g160.84590.47370.8766

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 116 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

A18B10C_tP116_130_2c4g_2c2g_a-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP116, then the space-group number 130, then the Wyckoff letters occupied by each element in turn (Sr: 4a; H: 4c; H: 4c; O: 4c; O: 4c; H: 16g; H: 16g; H: 16g; H: 16g; O: 16g; O: 16g). 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 A18B10C_tP116_130_2c4g_2c2g_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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