Cs₃Tl₂Cl₉ (K7₂)

Unit cell

Lattice constants

a = 12.796 Å, b = 12.796 Å, c = 18.297 Å; α = 90.00°, β = 90.00°, γ = 120.00°

Cell volume

2594.5 ų

Atoms in the conventional cell

84 (Tl 12, Cl 54, Cs 18)

Formula units Z

6

Pearson symbol

hR28 — hexagonal / trigonal, rhombohedral lattice, 28 atoms per conventional cell

Symmetry operations

36 per cell

Crystallographic sites

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 84 atoms drawn above are these sites multiplied by all 36 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

A9B3C2_hR28_167_ef_e_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hR28, then the space-group number 167, then the Wyckoff letters occupied by each element in turn (Tl: 12c; Cl: 18e; Cs: 18e; Cl: 36f). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Cs₃Dy₂Br₉, Cs₃Er₂Br₉, Cs₃Ho₂Br₉, Cs₃Lu₂Cl₉, Cs₃Tb₂Br₉, Cs₃Yb₂Br₉, Ba₃Os₂O₉, Ba₃W₂O₉ <!--beginning with an

Note: K7₂.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A9B3C2_hR28_167_ef_e_c-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.