Fapbi3 Cif File [LATEST - TIPS]

If you download a CIF for FAPbI₃ from a general database (e.g., CCDC), you might accidentally retrieve the stable δ-phase. Here is its signature:

_symmetry_space_group_name_H-M      'P 63 m c'
_cell_length_a                      8.980
_cell_length_c                      11.410

In this hexagonal structure, PbI₆ octahedra share faces to form chains, and the FA cations are ordered. This CIF is useless for solar cell simulation unless you are studying degradation. fapbi3 cif file

Once you have fapbi3.cif, you must check for errors. Bad CIFs lead to non-physical DFT energies. If you download a CIF for FAPbI₃ from

This is the highest symmetry cubic space group. It implies that the PbI₆ octahedra are perfectly aligned with no tilting. The CIF includes a loop_ of symmetry operations that generate the entire crystal from the asymmetric unit. In this hexagonal structure, PbI₆ octahedra share faces

Always "relax" the CIF before final production runs. Use:

At temperatures exceeding $\approx$ 330 K, FAPbI$_3$ stabilizes in a cubic structure.