Low Temperature Body-Centered Tetragonal CH₃NH₃PbBr₃ Br₃CH₆NPb

Unit cell

Lattice constants

a = 8.281 Å, b = 8.281 Å, c = 11.851 Å; α = 90.00°, β = 90.00°, γ = 90.00°

Cell volume

812.8 ų

Atoms in the conventional cell

272 (Br 12, Pb 4, C 32, H 192, N 32)

Formula units Z

4

Pearson symbol

tI272 — tetragonal, body-centred lattice, 272 atoms per conventional cell

Symmetry operations

32 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 272 atoms drawn above are these sites multiplied by all 32 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

A3B8C48D8E_tI272_140_ah_m_6m_m_c-001: the stoichiometry comes first (A, B, C… are the elements in alphabetical order of their site labels), then the Pearson symbol tI272, then the space-group number 140, then the Wyckoff letters occupied by each element in turn (Br: 4a; Pb: 4c; Br: 8h; C: 32m; H: 32m; H: 32m; H: 32m; H: 32m; H: 32m; H: 32m; N: 32m). Two structures with the same label are the same arrangement with different cell parameters or coordinates.

Note: LT-TET.

Source

Coordinates and cell from the AFLOW Encyclopedia of Crystallographic Prototypes, entry A3B8C48D8E_tI272_140_ah_m_6m_m_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.