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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Ho3TaO7 by Materials Project

Ho3TaO7 crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. there are two inequivalent Ho3+ sites. In the first 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 2.32–2.39 Å. In the second Ho3+ site, Ho3+ is bonded to seven O2- atoms to form distorted HoO7 pentagonal bipyramids that share corners with two equivalent TaO6 octahedra, a cornercorner with one HoO7 pentagonal bipyramid, edges with two equivalent TaO6 octahedra, and edges with three equivalent HoO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 38–50°. There are a spread of Ho–O bond distances ranging from 2.21–2.45 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent HoO7 pentagonal bipyramids, and edges with four equivalent HoO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 43°. There are a spread of Ta–O bond distances ranging from 1.93–2.05 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ho3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded to four Ho3+ atoms to form a mixture of edge and corner-sharing OHo4 tetrahedra. In the third O2- site, O2- is bonded to four Ho3+ atoms to form a mixture of edge and corner-sharing OHo4 tetrahedra. In the fourth O2- site, O2- is bonded to three Ho3+ and one Ta5+ atom to form a mixture of distorted edge and corner-sharing OHo3Ta tetrahedra. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ho3+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3TaO7 by Materials Project

Ho3TaO7 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are six inequivalent Ho3+ sites. In the first Ho3+ site, Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with two equivalent HoO6 octahedra and corners with two TaO4 tetrahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Ho–O bond distances ranging from 2.16–2.40 Å. In the second Ho3+ site, Ho3+ is bonded to six O2- atoms to form distorted HoO6 octahedra that share corners with two equivalent HoO6 octahedra and corners with two TaO4 tetrahedra. The corner-sharing octahedral tilt angles are 64°. There are a spread of Ho–O bond distances ranging from 2.17–2.41 Å. In the third Ho3+ site, Ho3+ is bonded in a 5-coordinate geometry to six O2- atoms. There are a spread of Ho–O bond distances ranging from 2.15–2.72 Å. In the fourth 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 2.15–2.80 Å. In the fifth 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 2.13–2.71 Å. In the sixth 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 2.13–2.68 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to four O2- atoms to form distorted TaO4 tetrahedra that share corners with two HoO6 octahedra and a cornercorner with one TaO5 tetrahedra. The corner-sharing octahedra tilt angles range from 60–63°. There is two shorter (1.90 Å) and two longer (1.91 Å) Ta–O bond length. In the second Ta5+ site, Ta5+ is bonded to five O2- atoms to form distorted TaO5 tetrahedra that share corners with two HoO6 octahedra and a cornercorner with one TaO4 tetrahedra. The corner-sharing octahedra tilt angles range from 61–63°. There are a spread of Ta–O bond distances ranging from 1.90–2.47 Å. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ho3+ atoms to form corner-sharing OHo4 tetrahedra. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ho3+ atoms. In the third O2- site, O2- is bonded to four Ho3+ atoms to form corner-sharing OHo4 tetrahedra. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two Ho3+ and one Ta5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to three Ho3+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ta5+ atom. In the ninth O2- site, O2- is bonded in a 2-coordinate geometry to one Ho3+ and two Ta5+ atoms. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to three Ho3+ atoms. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to three Ho3+ and one Ta5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Ho3+ and one Ta5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to three Ho3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho3TaO7 by Materials Project

Ho3TaO7 crystallizes in the orthorhombic Cmme 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 corner-sharing HoO6 octahedra. The corner-sharing octahedral tilt angles are 70°. There are two shorter (2.26 Å) and four longer (2.27 Å) Ho–O bond lengths. 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 2.08–2.56 Å. Ta5+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.16 Å) and four longer (2.18 Å) Ta–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ho3+ atoms to form OHo4 tetrahedra that share corners with ten OHo4 tetrahedra and edges with four equivalent OHo3Ta tetrahedra. In the second O2- site, O2- is bonded to three Ho3+ and one Ta5+ atom to form a mixture of distorted edge and corner-sharing OHo3Ta tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ho3+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗