Fapbi3 Cif File Link
Below is a simplified, representative CIF for cubic FAPbI₃ (experimental data may vary slightly depending on temperature and synthesis):
data_FAPbI3_cubic _audit_creation_method 'generated by VESTA' _cell_length_a 6.362 _cell_length_b 6.362 _cell_length_c 6.362 _cell_angle_alpha 90 _cell_angle_beta 90 _cell_angle_gamma 90 _space_group_name_H-M_alt 'Pm-3m' _space_group_IT_number 221loop_ _space_group_symop_operation_xyz 'x, y, z' '-x, -y, z' '-x, y, -z' 'x, -y, -z' 'z, x, y' ...
loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy Pb Pb 0.00000 0.00000 0.00000 1.0 I I 0.00000 0.00000 0.50000 1.0 FA C 0.50000 0.50000 0.50000 1.0 FA N 0.50000 0.50000 0.50000 0.5 # simplified representationfapbi3 cif file
⚠️ Note: In real CIFs, the FA cation (HC(NH₂)₂⁺) is often modeled with multiple atoms (C, N, H) at specific fractional coordinates. Hydrogen atoms may be omitted or included with partial occupancies due to disorder. Below is a simplified, representative CIF for cubic
The crystallography of hybrid organic-inorganic perovskites (HOIPs) is complicated by the dynamic disorder of the organic A-site cation. In FAPbI$_3$, the FA$^+$ ion is larger than the MA$^+$ ion (ionic radius $\approx$ 2.53 Å vs 2.17 Å), exerting higher internal pressure on the PbI$_6$ octahedral framework. This results in a delicate thermodynamic balance between the cubic perovskite phase ($\alpha$-FAPbI$_3$) and the yellow, non-perovskite hexagonal phase ($\delta$-FAPbI$_3$).
This paper analyzes the CIF parameters associated with the high-temperature cubic phase ($\approx$ 330 K) and discusses the crystallographic implications of the space group assignment, specifically the debated assignment between $Pm\bar3m$ (No. 221) and $Fm\bar3m$ (No. 225). ⚠️ Note: In real CIFs, the FA cation
The _atom_site_B_iso_or_equiv values (in Ų) indicate atomic vibration:
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.