DOI: 10.17188/1298485
title: Materials Data on Ho2Ti2O7 by Materials Project

description: Ho2Ti2O7 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.25–2.72 Å. In the second Ho3+ site, Ho3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.23–2.39 Å. In the third Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.23–2.45 Å. In the fourth Ho3+ site, Ho3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ho–O bond distances ranging from 2.33–2.61 Å. There are four inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 30–45°. There are a spread of Ti–O bond distances ranging from 1.87–2.20 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 26–45°. There are a spread of Ti–O bond distances ranging from 1.83–2.29 Å. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 30–50°. There are a spread of Ti–O bond distances ranging from 1.78–2.28 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 26–50°. There are a spread of Ti–O bond distances ranging from 1.82–2.34 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to two Ho3+ and two Ti4+ atoms to form distorted OHo2Ti2 tetrahedra that share corners with four OHo3Ti tetrahedra and an edgeedge with one OHo2Ti2 tetrahedra. In the second O2- site, O2- is bonded to three Ho3+ and one Ti4+ atom to form distorted OHo3Ti tetrahedra that share corners with five OHo2Ti2 tetrahedra and an edgeedge with one OHo3Ti tetrahedra. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ho3+ and two Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ho3+ and two Ti4+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three Ho3+ and one Ti4+ atom. In the sixth O2- site, O2- is bonded in a 5-coordinate geometry to three Ho3+ and two equivalent Ti4+ atoms. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to two Ho3+ and two Ti4+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ti4+ atom. In the ninth O2- site, O2- is bonded to two Ho3+ and two Ti4+ atoms to form a mixture of distorted edge and corner-sharing OHo2Ti2 tetrahedra. In the tenth O2- site, O2- is bonded in a distorted see-saw-like geometry to two Ho3+ and two Ti4+ atoms. In the eleventh O2- site, O2- is bonded to two Ho3+ and two Ti4+ atoms to form a mixture of distorted edge and corner-sharing OHo2Ti2 tetrahedra. In the twelfth O2- site, O2- is bonded to three Ho3+ and one Ti4+ atom to form a mixture of distorted edge and corner-sharing OHo3Ti tetrahedra. In the thirteenth O2- site, O2- is bonded in a 5-coordinate geometry to three Ho3+ and two equivalent Ti4+ atoms. In the fourteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ho3+ and two Ti4+ atoms.