Only unique atoms are listed; symmetry generates the rest.
This is a powerful tool for computational chemists.
FAPbI₃ (formamidinium lead iodide) is a hybrid organic-inorganic perovskite with the chemical formula HC(NH₂)₂PbI₃. It is a promising light-absorbing material in high-efficiency perovskite solar cells (PSCs) due to its optimal band gap (~1.48 eV) and excellent thermal stability compared to its methylammonium counterpart (MAPbI₃). fapbi3 cif file
The _atom_site_B_iso_or_equiv values (in Ų) indicate atomic vibration:
Below is a typical CIF entry for cubic α-FAPbI₃ at room temperature (simplified for clarity). We will break down each section. Only unique atoms are listed; symmetry generates the rest
data_FAPbI3_alpha _audit_creation_method 'Generated by VESTA' _cell_length_a 6.3620 _cell_length_b 6.3620 _cell_length_c 6.3620 _cell_angle_alpha 90.00 _cell_angle_beta 90.00 _cell_angle_gamma 90.00 _cell_volume 257.52 _symmetry_space_group_name_H-M 'Pm-3m' _symmetry_Int_Tables_number 221loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, -y, -z' ... (additional symmetry operators for cubic)
loop_ _atom_site_label _atom_site_type_symbol _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_occupancy _atom_site_B_iso_or_equiv Pb1 Pb 0.00000 0.00000 0.00000 1.00 2.50 I1 I 0.00000 0.00000 0.50000 1.00 3.00 I2 I 0.00000 0.50000 0.00000 1.00 3.00 I3 I 0.50000 0.00000 0.00000 1.00 3.00 FA1 C 0.50000 0.50000 0.50000 0.50 5.00 FA2 N 0.50000 0.50000 0.50000 1.00 4.50This is a powerful tool for computational chemists
Before downloading a CIF file, you must understand what phase you need.
If you are searching for this CIF file, you are likely working on perovskite solar cells. FAPbI$_3$ is prized for its ideal bandgap (~1.48 eV), making it more efficient for solar absorption than its cousin, MAPbI$_3$ (Methylammonium Lead Iodide).
You convert the CIF into a POSCAR or .in file. The cubic cell allows for fast k-point sampling. However, note that DFT often requires relaxing the structure (especially the H atoms of FA, which are missing in basic CIFs).