Materials Data on SrCa4(FeO2)5 by Materials Project
SrCa4(FeO2)5 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 2.66 Å. There are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.56 Å) and four longer (2.58 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded in a body-centered cubic geometry to eight O2- atoms. All Ca–O bond lengths are 2.59 Å. There are three 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 rectangular see-saw-like geometry to four equivalent O2- atoms. All Fe–O bond lengths are 2.01 Å. In the third 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 three 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 edge, corner, and face-sharing OSr2Ca2Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. In the second O2- site, O2- is bonded to four 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°. In the third O2- site, O2- is bonded to four equivalent Ca2+ and two equivalent Fe2+ atoms to form a mixture of edge, corner, and face-sharing OCa4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–67°.