DOI: 10.17188/1207570
title: Materials Data on Ho10Ti6O27 by Materials Project

description: Ho10Ti6O27 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are seven inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to seven O2- atoms to form distorted HoO7 pentagonal bipyramids that share a cornercorner with one HoO6 octahedra, a cornercorner with one HoO7 pentagonal bipyramid, and an edgeedge with one HoO7 pentagonal bipyramid. The corner-sharing octahedral tilt angles are 71°. There are a spread of Ho–O bond distances ranging from 2.17–2.43 Å. 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 2.14–2.37 Å. In the third Ho3+ site, Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with two equivalent HoO7 pentagonal bipyramids and a cornercorner with one TiO5 trigonal bipyramid. There are a spread of Ho–O bond distances ranging from 2.19–2.39 Å. In the fourth 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 2.16–2.47 Å. In the fifth Ho3+ site, Ho3+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Ho–O bond distances ranging from 2.10–2.74 Å. In the sixth Ho3+ site, Ho3+ is bonded in a 3-coordinate geometry to five O2- atoms. There are a spread of Ho–O bond distances ranging from 2.13–2.61 Å. In the seventh 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 2.15–2.51 Å. There are five inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.86–2.28 Å. In the second Ti4+ site, Ti4+ is bonded to five O2- atoms to form distorted TiO5 trigonal bipyramids that share a cornercorner with one HoO6 octahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Ti–O bond distances ranging from 1.88–2.07 Å. In the third Ti4+ site, Ti4+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ti–O bond distances ranging from 1.85–2.36 Å. In the fourth Ti4+ site, Ti4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.93–2.21 Å. In the fifth Ti4+ site, Ti4+ is bonded in a 5-coordinate geometry to seven O2- atoms. There are a spread of Ti–O bond distances ranging from 1.89–2.54 Å. There are nineteen inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Ho3+ and two Ti4+ atoms to form distorted OHo2Ti2 tetrahedra that share corners with two OHo3Ti tetrahedra, an edgeedge with one OHo3Ti tetrahedra, and an edgeedge with one OTi4 trigonal pyramid. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ti4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and two Ti4+ atoms. In the fourth O2- site, O2- is bonded to three Ho3+ and one Ti4+ atom to form OHo3Ti tetrahedra that share corners with three OHo3Ti tetrahedra and edges with two OHo2Ti2 tetrahedra. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ho3+ and one Ti4+ atom. In the sixth O2- site, O2- is bonded to three Ho3+ and one Ti4+ atom to form distorted OHo3Ti tetrahedra that share corners with ten OHo4 tetrahedra and edges with two equivalent OHo2Ti2 tetrahedra. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to three Ho3+ and one Ti4+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ho3+ and two equivalent Ti4+ atoms. In the ninth O2- site, O2- is bonded to three Ho3+ and one Ti4+ atom to form distorted OHo3Ti tetrahedra that share corners with five OHo4 tetrahedra and edges with three OHo3Ti tetrahedra. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Ho3+ and two Ti4+ atoms. In the eleventh O2- site, O2- is bonded to four Ho3+ atoms to form a mixture of edge and corner-sharing OHo4 tetrahedra. In the twelfth O2- site, O2- is bonded in a 4-coordinate geometry to three Ho3+ and one Ti4+ atom. In the thirteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Ho3+ and one Ti4+ atom. In the fourteenth O2- site, O2- is bonded to two Ho3+ and two equivalent Ti4+ atoms to form distorted OHo2Ti2 tetrahedra that share corners with three OHo4 tetrahedra and an edgeedge with one OTi4 trigonal pyramid. In the fifteenth O2- site, O2- is bonded to two equivalent Ho3+ and two Ti4+ atoms to form distorted OHo2Ti2 tetrahedra that share corners with six OHo2Ti2 tetrahedra, a cornercorner with one OTi4 trigonal pyramid, and edges with two equivalent OHo2Ti2 tetrahedra. In the sixteenth O2- site, O2- is bonded to three Ho3+ and one Ti4+ atom to form a mixture of edge and corner-sharing OHo3Ti tetrahedra. In the seventeenth 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 eighteenth O2- site, O2- is bonded to four Ti4+ atoms to form a mixture of distorted edge and corner-sharing OTi4 trigonal pyramids. In the nineteenth O2- site, O2- is bonded to three Ho3+ and one Ti4+ atom to form distorted OHo3Ti tetrahedra that share corners with six OHo2Ti2 tetrahedra, a cornercorner with one OTi4 trigonal pyramid, and edges with three OHo4 tetrahedra.