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Room Temperature Perovskite CH₃NH₃PbBr₃ Br₃CH₆NPb

Cubic · space group Pm-3m (No. 221) · Pearson cP172

Symmetry elements and Wyckoff positions (interactive)

Room Temperature Perovskite CH₃NH₃PbBr₃ in Pm-3m

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

Unit cell

Lattice constants
a = 5.926 Å, b = 5.926 Å, c = 5.926 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
208.1 ų
Atoms in the conventional cell
172 (Pb 1, Br 3, C 12, N 12, H 144)
Formula units Z
1
Pearson symbol
cP172 — cubic, primitive lattice, 172 atoms per conventional cell
Symmetry operations
48 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Pb8Pb1b10.50000.50000.5000
Br1Br3c30.00000.50000.5000
C2C12i120.00000.94160.9416
N7N12i120.00000.10840.1084
H3H24k240.00000.05700.2390
H4H24k240.00000.02700.7780
H5H48n480.14800.21100.0840
H6H48n480.85200.83500.9540

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 172 atoms drawn above are these sites multiplied by all 48 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

A3B12C144D12E_cP172_221_c_i_2k2n_i_b-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol cP172, then the space-group number 221, then the Wyckoff letters occupied by each element in turn (Pb: 1b; Br: 3c; C: 12i; N: 12i; H: 24k; H: 24k; H: 48n; H: 48n). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: RT-Perovskite.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3B12C144D12E_cP172_221_c_i_2k2n_i_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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