If you download a CIF for FAPbI₃ from a general database (e.g., CCDC), you might accidentally retrieve the stable . Here is its signature:
Once you have the CIF, you can:
Formamidinium lead triiodide (HC(NH$_2$)$_2$PbI$_3$ or FAPbI$_3$) represents the forefront of next-generation photovoltaic materials, offering a reduced bandgap closer to the Shockley-Queisser optimum compared to its methylammonium counterpart. However, the structural instability of the photoactive perovskite phase ($\alpha$-phase) remains a critical bottleneck. This paper provides a comprehensive crystallographic analysis of the FAPbI$_3$ Crystallographic Information File (CIF), focusing on the temperature-dependent phase transitions from the cubic $Fm\bar3m$ (or pseudo-cubic $Pm\bar3m$) structure to the non-perovskite hexagonal $P6_3mc$ phase. Through simulated Rietveld refinement and group-subgroup analysis, we deconvolute the orientational disorder of the formamidinium cation and its impact on the lattice parameters, offering a definitive guide for interpreting experimental diffraction data.
Because it is a highly studied material, you don't need to write a CIF file from scratch. You can download structural data from open-access crystallographic databases to begin your simulations. Reliable resources include: fapbi3 cif file
has a narrower bandgap (~1.48 eV) than its counterpart, methylammonium lead iodide ( MAPbI3MAPbI sub 3
Unlike simple table salt, the Formamidinium ion in the center of the FAPbI
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). If you download a CIF for FAPbI₃ from
If you are looking to advance your research or computational work, let me know:
CIF file, researchers can quantify phase purity and detect unwanted -phase contamination. 3. Computational Simulations
The CIF file allows you to generate a theoretical powder XRD pattern. By comparing this simulated pattern with experimental data via Rietveld refinement (using software like or GSAS-II ), you can quantify the phase purity of your synthesized solar films. Where to Find Reliable FAPbI3 CIF Files she heard the hum begin again.
The "yellow phase." It consists of face-sharing octahedra, which traps charges and prevents efficient solar energy conversion.
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).
For FAPbI₃, the CIF file captures the delicate balance between its black (cubic, photoactive) and yellow δ-phase (hexagonal, non-photoactive).
) in performance due to its superior bandgap and thermal stability. To simulate, analyze, or visualize the atomic structure of this material, researchers rely on a (Crystallographic Information Framework). This article provides an in-depth guide to the FAPbI3FAPbI sub 3
But as she walked out, she heard the hum begin again.