Materials Data on Sr7Ca(IrO6)2 by Materials Project
Sr7Ca(IrO6)2 crystallizes in the trigonal R32 space group. The structure is three-dimensional. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.56–2.83 Å. In the second Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.58–2.81 Å. In the third Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Sr–O bond lengths are 2.46 Å. Ca2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ca–O bond lengths are 2.37 Å. Ir4+ is bonded in an octahedral geometry to six O2- atoms. There are three shorter (2.07 Å) and three longer (2.08 Å) Ir–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to five Sr2+ and one Ir4+ atom to form a mixture of distorted edge, face, and corner-sharing OSr5Ir octahedra. The corner-sharing octahedra tilt angles range from 1–64°. In the second O2- site, O2- is bonded to four Sr2+, one Ca2+, and one Ir4+ atom to form a mixture of distorted edge, face, and corner-sharing OSr4CaIr octahedra. The corner-sharing octahedra tilt angles range from 1–64°.