Materials Data on Ho2Sb2O7 by Materials Project
Ho2Sb2O7 crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. there are two inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with six SbO6 octahedra and edges with two equivalent SbO6 octahedra. The corner-sharing octahedra tilt angles range from 61–69°. There are two shorter (2.22 Å) and four longer (2.37 Å) Ho–O bond lengths. In the second Ho3+ site, Ho3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.38 Å) and four longer (2.59 Å) Ho–O bond lengths. There are two inequivalent Sb4+ sites. In the first Sb4+ site, Sb4+ is bonded to six O2- atoms to form SbO6 octahedra that share corners with four equivalent HoO6 octahedra and corners with six SbO6 octahedra. The corner-sharing octahedra tilt angles range from 14–61°. There is two shorter (1.94 Å) and four longer (2.01 Å) Sb–O bond length. In the second Sb4+ site, Sb4+ is bonded to six O2- atoms to form distorted SbO6 octahedra that share corners with two equivalent HoO6 octahedra, corners with four equivalent SbO6 octahedra, and edges with two equivalent HoO6 octahedra. The corner-sharing octahedra tilt angles range from 60–69°. There are two shorter (2.26 Å) and four longer (2.35 Å) Sb–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ho3+ and two Sb4+ atoms. In the second O2- site, O2- is bonded to three Ho3+ and one Sb4+ atom to form a mixture of corner and edge-sharing OHo3Sb tetrahedra. In the third O2- site, O2- is bonded in a linear geometry to two equivalent Sb4+ atoms.