Crystal Lab › Prototype structures › Hexagonal
BaSi₄O₉ (S3₂)
Hexagonal · space group P-6c2 (No. 188) · Pearson hP28 · Strukturbericht S32
Symmetry elements and Wyckoff positions (interactive)
BaSi₄O₉ (S3₂) in P-6c2
SettingUnit cell
- Lattice constants
- a = 6.495 Å, b = 6.495 Å, c = 9.347 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 341.5 ų
- Atoms in the conventional cell
- 28 (Ba 2, Si 8, O 18)
- Formula units Z
- 2
- Pearson symbol
- hP28 — hexagonal / trigonal, primitive lattice, 28 atoms per conventional cell
- Symmetry operations
- 12 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Ba1 | Ba | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Si4 | Si | 2c | 2 | 0.3333 | 0.6667 | 0.0000 |
| O2 | O | 6k | 6 | 0.4044 | 0.1497 | 0.2500 |
| Si5 | Si | 6k | 6 | 0.4536 | 0.4210 | 0.2500 |
| O3 | O | 12l | 12 | 0.5626 | 0.6679 | 0.6032 |
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 28 atoms drawn above are these sites multiplied by all 12 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
AB9C4_hP28_188_a_kl_ck-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP28, then the space-group number 188, then the Wyckoff letters occupied by each element in turn (Ba: 2a; Si: 2c; O: 6k; Si: 6k; O: 12l). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Ba(Si_{x}Ti_{1-x})Si₃O₉ (pabstite), BaSnGe₃O₉, BaTiSi₃O₉ (benitoite), BaZrSi₃O₉ (bazrite), CaKP₃O₉, MgKP₃O₉, TaKGe₃O₉, TaRbGe₃O₉, TaTlGe₃O₉ <!--beginning with an
Note: S3₂.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB9C4_hP28_188_a_kl_ck-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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