Crystal Lab › Prototype structures › Tetragonal
Be[BH₄]₂ B₂BeH₈
Tetragonal · space group I41cd (No. 110) · Pearson tI176
Symmetry elements and Wyckoff positions (interactive)
Be[BH₄]₂ in I41cd
SettingUnit cell
- Lattice constants
- a = 13.620 Å, b = 13.620 Å, c = 9.100 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 1688.1 ų
- Atoms in the conventional cell
- 176 (B 32, Be 16, H 128)
- Formula units Z
- 16
- Pearson symbol
- tI176 — tetragonal, body-centred lattice, 176 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| B1 | B | 16b | 16 | 0.5491 | 0.8362 | 0.2590 |
| B2 | B | 16b | 16 | 0.3065 | 0.1386 | 0.8704 |
| Be3 | Be | 16b | 16 | 0.1998 | 0.0869 | 0.0000 |
| H10 | H | 16b | 16 | 0.2286 | 0.1450 | 0.8515 |
| H11 | H | 16b | 16 | 0.3150 | 0.0899 | 0.9761 |
| H4 | H | 16b | 16 | 0.5687 | 0.9045 | 0.3098 |
| H5 | H | 16b | 16 | 0.6012 | 0.7807 | 0.2082 |
| H6 | H | 16b | 16 | 0.5033 | 0.7931 | 0.3482 |
| H7 | H | 16b | 16 | 0.1413 | 0.0083 | 0.9159 |
| H8 | H | 16b | 16 | 0.3436 | 0.1054 | 0.7752 |
| H9 | H | 16b | 16 | 0.3374 | 0.2122 | 0.8904 |
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 176 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
A2BC8_tI176_110_2b_b_8b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI176, then the space-group number 110, then the Wyckoff letters occupied by each element in turn (B: 16b; B: 16b; Be: 16b; H: 16b; H: 16b; H: 16b; H: 16b; H: 16b; H: 16b; H: 16b; H: 16b). 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 A2BC8_tI176_110_2b_b_8b-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.