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Crystal Lab › Prototype structures › Hexagonal

Crancrinite (Na₆Ca₂Al₆Si₆O₂₄(CO₃)₂, S3_3(I))

Hexagonal · space group P63 (No. 173) · Pearson hP52 · Strukturbericht S33(I) · mineral: crancrinite

Symmetry elements and Wyckoff positions (interactive)

Crancrinite (Na₆Ca₂Al₆Si₆O₂₄(CO₃)₂, S3_3(I)) in P63

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

Unit cell

Lattice constants
a = 12.720 Å, b = 12.720 Å, c = 5.180 Å; α = 90.00°, β = 90.00°, γ = 120.00°
Cell volume
725.8 ų
Atoms in the conventional cell
52 (C 2, Ca 2, Al 6, Na 6, O 30, Si 6)
Formula units Z
2
Pearson symbol
hP52 — hexagonal / trigonal, primitive lattice, 52 atoms per conventional cell
Symmetry operations
6 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
C2C2b20.33330.66670.3600
Ca3Ca2b20.33330.66670.8600
Al1Al6c60.26000.23000.2400
Na4Na6c60.50000.50000.2200
O5O6c60.05000.36000.0100
O6O6c60.36000.32000.9700
O7O6c60.17000.27000.2600
O8O6c60.87000.16000.2400
O9O6c60.20000.64000.3600
Si10Si6c60.03300.26000.2600

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 52 atoms drawn above are these sites multiplied by all 6 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

A3BCD3E15F3_hP52_173_c_b_b_c_5c_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP52, then the space-group number 173, then the Wyckoff letters occupied by each element in turn (C: 2b; Ca: 2b; Al: 6c; Na: 6c; O: 6c; O: 6c; O: 6c; O: 6c; O: 6c; Si: 6c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: S3₃(I), Crancrinite.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3BCD3E15F3_hP52_173_c_b_b_c_5c_c-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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