Crystal Lab › Prototype structures › Tetragonal
CaV₄O₉
Tetragonal · space group P4/n (No. 85) · Pearson tP28
Symmetry elements and Wyckoff positions (interactive)
CaV₄O₉ in P4/n
SettingUnit cell
- Lattice constants
- a = 8.333 Å, b = 8.333 Å, c = 5.008 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 347.7 ų
- Atoms in the conventional cell
- 28 (O 18, Ca 2, V 8)
- Formula units Z
- 2
- Pearson symbol
- tP28 — tetragonal, primitive lattice, 28 atoms per conventional cell
- Symmetry operations
- 8 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| O1 | O | 2a | 2 | 0.0000 | 0.0000 | 0.0000 |
| Ca2 | Ca | 2c | 2 | 0.0000 | 0.5000 | 0.6674 |
| O3 | O | 8g | 8 | 0.7940 | 0.6070 | 0.9640 |
| O4 | O | 8g | 8 | 0.9270 | 0.7490 | 0.4390 |
| V5 | V | 8g | 8 | 0.9084 | 0.7866 | 0.1256 |
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 28 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
AB9C4_tP28_85_c_a2g_g-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP28, then the space-group number 85, then the Wyckoff letters occupied by each element in turn (O: 2a; Ca: 2c; O: 8g; O: 8g; V: 8g). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
SrV₄O₉ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB9C4_tP28_85_c_a2g_g-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.