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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Pr3TaO7 by Materials Project

Pr3TaO7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Pr3+ sites. In the first Pr3+ site, Pr3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.43 Å) and four longer (2.78 Å) Pr–O bond lengths. In the second Pr3+ site, Pr3+ is bonded to seven O2- atoms to form distorted PrO7 pentagonal bipyramids that share corners with two equivalent TaO6 octahedra, corners with three equivalent PrO7 pentagonal bipyramids, edges with two equivalent TaO6 octahedra, and edges with two equivalent PrO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of Pr–O bond distances ranging from 2.33–2.74 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent PrO7 pentagonal bipyramids, and edges with four equivalent PrO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 29°. There are two shorter (2.00 Å) and four longer (2.01 Å) Ta–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Pr3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded to four Pr3+ atoms to form a mixture of edge and corner-sharing OPr4 tetrahedra. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Pr3+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PrTaO4 by Materials Project

PrTaO4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Pr3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Pr–O bond distances ranging from 2.35–2.89 Å. Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 31–42°. There are a spread of Ta–O bond distances ranging from 1.93–2.07 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Pr3+ and one Ta5+ atom. In the second O2- site, O2- is bonded to three equivalent Pr3+ and one Ta5+ atom to form a mixture of distorted edge and corner-sharing OPr3Ta tetrahedra. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Pr3+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Pr3+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PrTa3O9 by Materials Project

PrTa3O9 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Pr3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Pr–O bond distances ranging from 2.48–2.56 Å. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded to six O2- atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 27–47°. There are a spread of Ta–O bond distances ranging from 1.86–2.21 Å. In the second Ta5+ site, Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 27–47°. There are a spread of Ta–O bond distances ranging from 1.96–2.03 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Ta5+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Pr3+ and two Ta5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Pr3+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Pr3+ and two equivalent Ta5+ atoms to form a mixture of distorted corner and edge-sharing OPr2Ta2 tetrahedra. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Pr3+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PrTa7O19 by Materials Project

PrTa7O19 crystallizes in the hexagonal P-6c2 space group. The structure is three-dimensional. Pr3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are six shorter (2.48 Å) and two longer (2.65 Å) Pr–O bond lengths. There are two inequivalent Ta5+ sites. In the first Ta5+ site, Ta5+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ta–O bond distances ranging from 1.93–2.51 Å. In the second Ta5+ site, Ta5+ is bonded in an octahedral geometry to six equivalent O2- atoms. All Ta–O bond lengths are 2.00 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Pr3+ and three equivalent Ta5+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Pr3+ and two Ta5+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ta5+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗