Crystal Lab › Prototype structures › Tetragonal
HfCuSi₂
Tetragonal · space group P4/nmm (No. 129) · Pearson tP8
Symmetry elements and Wyckoff positions (interactive)
HfCuSi₂ in P4/nmm
SettingUnit cell
- Lattice constants
- a = 3.732 Å, b = 3.732 Å, c = 8.990 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 125.2 ų
- Atoms in the conventional cell
- 8 (Cu 2, Si 4, Hf 2)
- Formula units Z
- 2
- Pearson symbol
- tP8 — tetragonal, primitive lattice, 8 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Cu1 | Cu | 2a | 2 | 0.7500 | 0.2500 | 0.0000 |
| Si3 | Si | 2b | 2 | 0.7500 | 0.2500 | 0.5000 |
| Hf2 | Hf | 2c | 2 | 0.2500 | 0.2500 | 0.7410 |
| Si4 | Si | 2c | 2 | 0.2500 | 0.2500 | 0.1890 |
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 8 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
ABC2_tP8_129_a_c_bc-002: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP8, then the space-group number 129, then the Wyckoff letters occupied by each element in turn (Cu: 2a; Si: 2b; Hf: 2c; Si: 2c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
CeAsSb₂, DyZnSn₂, ErZnSn₂, GdZnSn₂, HfCuGe₂, HfCuSi₂, HoZnSn₂, LaAsSb₂, LuSn₂, TbAgSb₂, TbCuSb₂, TbPdSb₂, TmZnSn₂, YZnSn₂, YbMnBi₂, YbMnSb₂, ZrCuGe₂, ZrCuSi₂ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry ABC2_tP8_129_a_c_bc-002 (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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