Hexagonal Hollandite (BaRu₄Cr₂O₁₂)

Unit cell

Lattice constants

a = 9.888 Å, b = 9.888 Å, c = 9.121 Å; α = 90.00°, β = 90.00°, γ = 90.00°

Cell volume

891.8 ų

Atoms in the conventional cell

76 (Ba 4, Cr 8, O 48, Ru 16)

Formula units Z

4

Pearson symbol

tP76 — tetragonal, primitive lattice, 76 atoms per conventional cell

Symmetry operations

4 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 76 atoms drawn above are these sites multiplied by all 4 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

AB2C12D4_tP76_75_2a2b_2d_12d_4d-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tP76, then the space-group number 75, then the Wyckoff letters occupied by each element in turn (Ba: 1a; Ba: 1a; Ba: 1b; Ba: 1b; Cr: 4d; Cr: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; O: 4d; Ru: 4d; Ru: 4d; Ru: 4d; Ru: 4d). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: Hexagonal hollandite.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB2C12D4_tP76_75_2a2b_2d_12d_4d-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.