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Crystal Lab › Prototype structures › Tetragonal

Luzonite (Cu₃AsS₄)

Tetragonal · space group I-42m (No. 121) · Pearson tI16 · mineral: luzonite

Symmetry elements and Wyckoff positions (interactive)

Luzonite (Cu₃AsS₄) in I-42m

Setting
Loading the group…
x = 0.10, y = 0.17, z = 0.08

Unit cell

Lattice constants
a = 5.330 Å, b = 5.330 Å, c = 10.570 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
300.3 ų
Atoms in the conventional cell
16 (As 2, Cu 6, S 8)
Formula units Z
2
Pearson symbol
tI16 — tetragonal, body-centred lattice, 16 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
As1As2a20.00000.00000.0000
Cu2Cu2b20.00000.00000.5000
Cu3Cu4d40.00000.50000.2500
S4S8i80.24420.24420.1248

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 16 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

AB3C4_tI16_121_a_bd_i-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI16, then the space-group number 121, then the Wyckoff letters occupied by each element in turn (As: 2a; Cu: 2b; Cu: 4d; S: 8i). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Ag₃VO₄, Cu₃SbS₄, Cu₃SbSe₄, Cu₃AsSe₄, Cu₃FeS₄, Cu₃VO₄, Si₃NiP₄ <!--beginning with an

Note: Luzonite.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3C4_tI16_121_a_bd_i-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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