Skip to content

Crystal Lab › Prototype structures › Hexagonal

Na₃As

Hexagonal · space group P63cm (No. 185) · Pearson hP24

Symmetry elements and Wyckoff positions (interactive)

Na₃As in P63cm

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

Unit cell

Lattice constants
a = 8.784 Å, b = 8.784 Å, c = 8.999 Å; α = 90.00°, β = 90.00°, γ = 120.00°
Cell volume
601.3 ų
Atoms in the conventional cell
24 (Na 18, As 6)
Formula units Z
6
Pearson symbol
hP24 — hexagonal / trigonal, primitive lattice, 24 atoms per conventional cell
Symmetry operations
12 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Na2Na2a20.00000.00000.2684
Na3Na4b40.33330.66670.2311
As1As6c60.33210.00000.2500
Na4Na6c60.31530.00000.5863
Na5Na6c60.35180.00000.9231

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 24 atoms drawn above are these sites multiplied by all 12 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

AB3_hP24_185_c_ab2c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol hP24, then the space-group number 185, then the Wyckoff letters occupied by each element in turn (Na: 2a; Na: 4b; As: 6c; Na: 6c; Na: 6c). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Other compounds with this structure

Cu₃P <!--beginning with an

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry AB3_hP24_185_c_ab2c-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.

← Stibiopalladinite (Pd₅Sb₂)  ·  Space group P63cm (7 prototypes)  ·  All prototypes  ·  LuMnO₃ →