Crystal Lab › Prototype structures › Trigonal
Brucite [Mg(OH)₂]
Trigonal · space group P-3m1 (No. 164) · Pearson hP5 · mineral: brucite
Symmetry elements and Wyckoff positions (interactive)
Brucite [Mg(OH)₂] in P-3m1
SettingUnit cell
- Lattice constants
- a = 3.150 Å, b = 3.150 Å, c = 4.770 Å; α = 90.00°, β = 90.00°, γ = 120.00°
- Cell volume
- 41.0 ų
- Atoms in the conventional cell
- 5 (Mg 1, H 2, O 2)
- Formula units Z
- 1
- Pearson symbol
- hP5 — hexagonal / trigonal, primitive lattice, 5 atoms per conventional cell
- Symmetry operations
- 12 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Mg2 | Mg | 1a | 1 | 0.0000 | 0.0000 | 0.0000 |
| H1 | H | 2d | 2 | 0.3333 | 0.6667 | 0.4130 |
| O3 | O | 2d | 2 | 0.3333 | 0.6667 | 0.2203 |
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 5 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
A2BC2_hP5_164_d_a_d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP5, then the space-group number 164, then the Wyckoff letters occupied by each element in turn (Mg: 1a; H: 2d; O: 2d). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Ca(OH)₂ (Portlandite), Fe(OH)₂, Mn(OH)₂ (Pyrochroite), Ni(OH)₂ (Theophrastite), β-Co(OH)₂ <!--beginning with an
Note: Brucite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC2_hP5_164_d_a_d-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.
← TbLiCu₂P₂ · Space group P-3m1 (34 prototypes) · All prototypes · K₂Pt(SCN)₆ (H6₃) →