Crystal Lab › Prototype structures › Orthorhombic
Eriochalcite (CuCl₂cdot2H₂O, C45)
Orthorhombic · space group Pmna (No. 53) · Pearson oP18 · Strukturbericht C45 · mineral: eriochalcite
Symmetry elements and Wyckoff positions (interactive)
Eriochalcite (CuCl₂cdot2H₂O, C45) in Pmna
SettingUnit cell
- Lattice constants
- a = 8.089 Å, b = 3.746 Å, c = 7.414 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 224.6 ų
- Atoms in the conventional cell
- 18 (Cu 2, O 4, Cl 4, H 8)
- Formula units Z
- 2
- Pearson symbol
- oP18 — orthorhombic, primitive lattice, 18 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cu2 | Cu | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| O4 | O | 4e | 4 | 0.2402 | 0.0000 | 0.0000 |
| Cl1 | Cl | 4h | 4 | 0.0000 | 0.3798 | 0.2400 |
| H3 | H | 8i | 8 | 0.2750 | 0.0640 | 0.0990 |
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 18 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
A2BC4D2_oP18_53_h_a_i_e-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oP18, then the space-group number 53, then the Wyckoff letters occupied by each element in turn (Cu: 2a; O: 4e; Cl: 4h; H: 8i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: C45, Eriochalcite.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2BC4D2_oP18_53_h_a_i_e-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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