Crystal Lab › Prototype structures › Orthorhombic
MgAlB₁₄
Orthorhombic · space group Imma (No. 74) · Pearson oI68
Symmetry elements and Wyckoff positions (interactive)
MgAlB₁₄ in Imma
SettingUnit cell
- Lattice constants
- a = 10.312 Å, b = 5.848 Å, c = 8.112 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 489.2 ų
- Atoms in the conventional cell
- 68 (Al 4, Mg 8, B 56)
- Formula units Z
- 4
- Pearson symbol
- oI68 — orthorhombic, body-centred lattice, 68 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Al1 | Al | 4a | 4 | 0.0000 | 0.0000 | 0.0000 |
| Mg7 | Mg | 8h | 8 | 0.0000 | 0.7831 | 0.6070 |
| B2 | B | 8i | 8 | 0.1639 | 0.2500 | 0.9229 |
| B3 | B | 8i | 8 | 0.0834 | 0.2500 | 0.7215 |
| B4 | B | 8i | 8 | 0.0988 | 0.2500 | 0.1290 |
| B5 | B | 16j | 16 | 0.6699 | 0.0007 | 0.2951 |
| B6 | B | 16j | 16 | 0.6874 | 0.9086 | 0.0866 |
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 68 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
AB14C2_oI68_74_a_3i2j_h-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oI68, then the space-group number 74, then the Wyckoff letters occupied by each element in turn (Al: 4a; Mg: 8h; B: 8i; B: 8i; B: 8i; B: 16j; B: 16j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
DyAlB₁₄, ErAlB₁₄, HoAlB₁₄, LiAlB₁₄, LuAlB₁₄, ScAlB₁₄, TbAlB₁₄, TmAlB₁₄, YbAlB₁₄ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB14C2_oI68_74_a_3i2j_h-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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