Materials Data on Ho2Zr2O7 by Materials Project
Ho2Zr2O7 crystallizes in the orthorhombic Pmma 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 a mixture of distorted edge and corner-sharing HoO6 octahedra. The corner-sharing octahedral tilt angles are 68°. There are two shorter (2.27 Å) and four longer (2.29 Å) Ho–O bond lengths. In the second Ho3+ site, Ho3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ho–O bond distances ranging from 2.17–2.31 Å. There are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.16–2.58 Å. In the second Zr4+ site, Zr4+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Zr–O bond distances ranging from 2.21–2.35 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ho3+ and two equivalent Zr4+ atoms to form OHo2Zr2 tetrahedra that share corners with ten OHo2Zr2 tetrahedra and an edgeedge with one OZr4 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Ho3+ and one Zr4+ atom. In the third O2- site, O2- is bonded to two equivalent Ho3+ and two equivalent Zr4+ atoms to form OHo2Zr2 tetrahedra that share corners with ten OHo2Zr2 tetrahedra and edges with five OZr4 tetrahedra. In the fourth O2- site, O2- is bonded to four Zr4+ atoms to form a mixture of edge and corner-sharing OZr4 tetrahedra. In the fifth O2- site, O2- is bonded to one Ho3+ and three Zr4+ atoms to form a mixture of edge and corner-sharing OHoZr3 tetrahedra.