Materials Data on Cr2Ir2O5 by Materials Project
Cr2Ir2O5 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Cr2+ is bonded in a 5-coordinate geometry to five O2- atoms. There are one shorter (2.00 Å) and four longer (2.09 Å) Cr–O bond lengths. There are two inequivalent Ir3+ sites. In the first Ir3+ site, Ir3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ir–O bond lengths are 2.10 Å. In the second Ir3+ site, Ir3+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Ir–O bond lengths are 2.42 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Cr2+ and two equivalent Ir3+ atoms to form OCr2Ir2 tetrahedra that share corners with two equivalent OCr2Ir4 octahedra, corners with ten equivalent OCr2Ir2 tetrahedra, and edges with five equivalent OCr2Ir2 tetrahedra. The corner-sharing octahedral tilt angles are 55°. In the second O2- site, O2- is bonded to two equivalent Cr2+ and four equivalent Ir3+ atoms to form OCr2Ir4 octahedra that share corners with four equivalent OCr2Ir4 octahedra, corners with eight equivalent OCr2Ir2 tetrahedra, and edges with four equivalent OCr2Ir4 octahedra. The corner-sharing octahedral tilt angles are 0°.