Materials Data on SrCa2(FeO2)3 by Materials Project
SrCa2(FeO2)3 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Sr2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Sr–O bond lengths are 2.67 Å. Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.57 Å) and four longer (2.58 Å) Ca–O bond lengths. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded in a rectangular see-saw-like geometry to four equivalent O2- atoms. All Fe–O bond lengths are 2.01 Å. In the second Fe2+ site, Fe2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Fe–O bond lengths are 2.01 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Sr2+, two equivalent Ca2+, and two equivalent Fe2+ atoms to form a mixture of distorted edge, face, and corner-sharing OSr2Ca2Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. In the second O2- site, O2- is bonded to four equivalent Ca2+ and two equivalent Fe2+ atoms to form OCa4Fe2 octahedra that share corners with fourteen OSr2Ca2Fe2 octahedra, edges with four OSr2Ca2Fe2 octahedra, and faces with four equivalent OCa4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°.