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
SettingUnit 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
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| C2 | C | 2b | 2 | 0.3333 | 0.6667 | 0.3600 |
| Ca3 | Ca | 2b | 2 | 0.3333 | 0.6667 | 0.8600 |
| Al1 | Al | 6c | 6 | 0.2600 | 0.2300 | 0.2400 |
| Na4 | Na | 6c | 6 | 0.5000 | 0.5000 | 0.2200 |
| O5 | O | 6c | 6 | 0.0500 | 0.3600 | 0.0100 |
| O6 | O | 6c | 6 | 0.3600 | 0.3200 | 0.9700 |
| O7 | O | 6c | 6 | 0.1700 | 0.2700 | 0.2600 |
| O8 | O | 6c | 6 | 0.8700 | 0.1600 | 0.2400 |
| O9 | O | 6c | 6 | 0.2000 | 0.6400 | 0.3600 |
| Si10 | Si | 6c | 6 | 0.0330 | 0.2600 | 0.2600 |
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.
← Sodium nepheline (Na_{8-x}Al_{8-x}Si_{8+x}O₃₂) · Space group P63 (10 prototypes) · All prototypes · PI₃ →