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Low Temperature Body-Centered Orthorhombic CH₃NH₃PbBr₃ Br₃CH₆NPb

Orthorhombic · space group Imma (No. 74) · Pearson oI192

Symmetry elements and Wyckoff positions (interactive)

Low Temperature Body-Centered Orthorhombic CH₃NH₃PbBr₃ in Imma

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

Unit cell

Lattice constants
a = 11.692 Å, b = 8.445 Å, c = 8.223 Å; α = 90.00°, β = 90.00°, γ = 90.00°
Cell volume
811.9 ų
Atoms in the conventional cell
192 (Pb 4, Br 12, C 16, H 144, N 16)
Formula units Z
4
Pearson symbol
oI192 — orthorhombic, body-centred lattice, 192 atoms per conventional cell
Symmetry operations
16 per cell

Crystallographic sites

SiteElementWyckoffMultiplicityxyz
Pb17Pb4c40.25000.25000.2500
Br1Br4e40.00000.25000.2050
Br2Br8f80.72520.00000.0000
C3C8h80.00000.13590.7195
H5H8h80.00000.32520.8665
H6H8h80.00000.11690.6030
N15N8h80.00000.30620.7500
C4C8i80.06870.25000.7500
N16N8i80.94390.25000.7500
H10H16j160.41630.85470.2212
H11H16j160.59630.64530.2788
H12H16j160.59630.77800.1424
H13H16j160.56780.85310.2019
H14H16j160.43220.58900.2676
H7H16j160.41630.67340.1712
H8H16j160.59630.82660.3288
H9H16j160.41630.72200.3576

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 192 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

A3B4C36D4E_oI192_74_ef_hi_2h8j_hi_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol oI192, then the space-group number 74, then the Wyckoff letters occupied by each element in turn (Pb: 4c; Br: 4e; Br: 8f; C: 8h; H: 8h; H: 8h; N: 8h; C: 8i; N: 8i; H: 16j; H: 16j; H: 16j; H: 16j; H: 16j; H: 16j; H: 16j; H: 16j). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: LT-BCO.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3B4C36D4E_oI192_74_ef_hi_2h8j_hi_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.

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