DOE OSTI2020
(CH3NH3)2FeCl4 crystallizes in the orthorhombic Pccn space group. The structure is two-dimensional and consists of eight methylammonium molecules and two FeCl4 sheets oriented in the (0, 0, 1) direction. In each FeCl4 sheet, Fe3+ is bonded to six Cl1- atoms to form corner-sharing FeCl6 octahedra. The corner-sharing octahedra tilt angles range from 1–18°. There are a spread of Fe–Cl bond distances ranging from 2.39–2.61 Å. There are three inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted bent 150 degrees geometry to two equivalent Fe3+ atoms. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Fe3+ atom. In the third Cl1- site, Cl1- is bonded in a linear geometry to two equivalent Fe3+ atoms.