The interpretation of the FAPbI$_3$ CIF is non-trivial due to the "orbits" of the FA cation.
) that is thermodynamically stable at room temperature but photo-inactive.
To understand the search query, we must deconstruct the string into standard chemical components.
Unlike the simpler cesium cation, the formamidinium (FA) molecule is a large, non-spherical organic cation. In a standard cubic CIF, the FA molecule often appears because it rotates rapidly within the lead-iodide "cage". This requires researchers to choose between a "time-averaged" CIF (useful for standard XRD refinement) and a "frozen" or relaxed structure (often derived from DFT calculations ) for modeling electronic band structures. Strategic Importance FAPbI3.cif - WMD-group/hybrid-perovskites - GitHub
) is dynamically disordered within the inorganic cage. CIF models often represent this via multiple occupancy sites or specific orientation minimizations, such as the fragment lying in the CIF Data Sources and Tools High-quality CIF files for FAPbI3cap F cap A cap P b cap I sub 3