Crystal Lab › Prototype structures › Tetragonal
Rb₂TiCu₂S₄
Tetragonal · space group P42/mcm (No. 132) · Pearson tP18
Symmetry elements and Wyckoff positions (interactive)
Rb₂TiCu₂S₄ in P42/mcm
SettingUnit cell
- Lattice constants
- a = 5.605 Å, b = 5.605 Å, c = 13.154 Å; α = 90.00°, β = 90.00°, γ = 90.00°
- Cell volume
- 413.2 ų
- Atoms in the conventional cell
- 18 (Ti 2, Cu 4, Rb 4, S 8)
- Formula units Z
- 2
- Pearson symbol
- tP18 — tetragonal, primitive lattice, 18 atoms per conventional cell
- Symmetry operations
- 16 per cell
Crystallographic sites
| Site | Element | Wyckoff | Multiplicity | x | y | z |
|---|---|---|---|---|---|---|
| Ti4 | Ti | 2b | 2 | 0.0000 | 0.0000 | 0.2500 |
| Cu1 | Cu | 4e | 4 | 0.0000 | 0.5000 | 0.2500 |
| Rb2 | Rb | 4i | 4 | 0.7369 | 0.7369 | 0.0000 |
| S3 | S | 8o | 8 | 0.7632 | 0.7632 | 0.3480 |
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 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
A2B2C4D_tP18_132_e_i_o_b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP18, then the space-group number 132, then the Wyckoff letters occupied by each element in turn (Ti: 2b; Cu: 4e; Rb: 4i; S: 8o). Two structures with the same label are the same arrangement with different cell parameters or coordinates.
Other compounds with this structure
Cs₂TiAg₂S₄, Cs₂TiCu₂Se₄ <!--beginning with an
Source
Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A2B2C4D_tP18_132_e_i_o_b-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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