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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on La3TaO7 by Materials Project

La3TaO7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.45 Å) and four longer (2.79 Å) La–O bond lengths. In the second La3+ site, La3+ is bonded to seven O2- atoms to form distorted LaO7 pentagonal bipyramids that share corners with two equivalent TaO6 octahedra, corners with three equivalent LaO7 pentagonal bipyramids, edges with two equivalent TaO6 octahedra, and edges with two equivalent LaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 39°. There are a spread of La–O bond distances ranging from 2.35–2.78 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra, corners with four equivalent LaO7 pentagonal bipyramids, and edges with four equivalent LaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 27°. All Ta–O bond lengths are 2.01 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four La3+ atoms to form a mixture of edge and corner-sharing OLa4 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Ta5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent La3+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaTaO4 by Materials Project

LaTaO4 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of La–O bond distances ranging from 2.39–3.03 Å. Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 12–38°. There are a spread of Ta–O bond distances ranging from 1.93–2.10 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one La3+ and two equivalent Ta5+ atoms. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent La3+ and two equivalent Ta5+ atoms. In the third O2- site, O2- is bonded to three equivalent La3+ and one Ta5+ atom to form distorted corner-sharing OLa3Ta tetrahedra. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent La3+ and one Ta5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LaTaO4 by Materials Project

LaTaO4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.37–2.86 Å. Ta5+ is bonded to six O2- atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 28–39°. There are a spread of Ta–O bond distances ranging from 1.94–2.07 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent La3+ and one Ta5+ atom. In the second O2- site, O2- is bonded to three equivalent La3+ and one Ta5+ atom to form a mixture of distorted edge and corner-sharing OLa3Ta tetrahedra. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one La3+ and two equivalent Ta5+ atoms. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one La3+ and two equivalent Ta5+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on La2Ta2O9 by Materials Project

La2Ta2O9 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. La is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of La–O bond distances ranging from 2.42–2.65 Å. Ta is bonded to six O atoms to form a mixture of distorted edge and corner-sharing TaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Ta–O bond distances ranging from 1.92–2.22 Å. There are five inequivalent O sites. In the first O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent La and two equivalent Ta atoms. In the second O site, O is bonded in a distorted T-shaped geometry to one La and two equivalent Ta atoms. In the third O site, O is bonded in a linear geometry to two equivalent Ta atoms. In the fourth O site, O is bonded in a 4-coordinate geometry to three equivalent La and one Ta atom. In the fifth O site, O is bonded in a distorted trigonal planar geometry to three equivalent La atoms.

36 MATERIALS SCIENCE↗