Crystal Lab › Prototype structures › Monoclinic
Bischofite (MgCl₂cdot6H₂O, J1₇)
Monoclinic · space group C12/m1 (No. 12) · Pearson mC42 · Strukturbericht J17 · mineral: bischofite
Symmetry elements and Wyckoff positions (interactive)
Bischofite (MgCl₂cdot6H₂O, J1₇) in C12/m1
SettingUnit cell
- Lattice constants
- a = 9.861 Å, b = 7.107 Å, c = 11.915 Å; α = 90.00°, β = 149.43°, γ = 90.00°
- Cell volume
- 424.7 ų
- Atoms in the conventional cell
- 42 (Mg 2, Cl 4, H 24, O 12)
- Formula units Z
- 2
- Pearson symbol
- mC42 — monoclinic, base-centred lattice, 42 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Mg6 | Mg | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Cl1 | Cl | 4i | 4 | 0.9298 | 0.0000 | 0.6122 |
| H2 | H | 4i | 4 | 0.4955 | 0.0000 | 0.2583 |
| H3 | H | 4i | 4 | 0.2776 | 0.0000 | 0.0083 |
| O7 | O | 4i | 4 | 0.3114 | 0.0000 | 0.1095 |
| H4 | H | 8j | 8 | 0.7993 | 0.7997 | 0.2784 |
| H5 | H | 8j | 8 | 0.6990 | 0.6984 | 0.3151 |
| O8 | O | 8j | 8 | 0.6804 | 0.7067 | 0.2233 |
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 42 atoms drawn above are these sites multiplied by all 8 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
A2B12CD6_mC42_12_i_2i2j_a_ij-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol mC42, then the space-group number 12, then the Wyckoff letters occupied by each element in turn (Mg: 2a; Cl: 4i; H: 4i; H: 4i; O: 4i; H: 8j; H: 8j; O: 8j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
MgBr₂cdot6H₂O <!--beginning with an
Note: J1₇, Bischofite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B12CD6_mC42_12_i_2i2j_a_ij-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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