Crystal Lab › Prototype structures › Tetragonal
β-Np (A_{d})
Tetragonal · space group P4/nmm (No. 129) · Pearson tP4 · Strukturbericht Ad
Symmetry elements and Wyckoff positions (interactive)
β-Np (A_{d}) in P4/nmm
SettingUnit cell
- Lattice constants
- a = 4.897 Å, b = 4.897 Å, c = 3.388 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 81.2 ų
- Atoms in the conventional cell
- 4 (Np 4)
- Formula units Z
- 4
- Pearson symbol
- tP4 — tetragonal, primitive lattice, 4 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Np1 | Np | 2a | 2 | 0.7500 | 0.2500 | 0.0000 |
| Np2 | Np | 2c | 2 | 0.2500 | 0.2500 | 0.3750 |
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 4 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
A_tP4_129_ac-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP4, then the space-group number 129, then the Wyckoff letters occupied by each element in turn (Np: 2a; Np: 2c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Note: A_{d}, \beta-Np.
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A_tP4_129_ac-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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