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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on NaU(Te3O8)2 by Materials Project

NaU(Te3O8)2 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. Na1+ is bonded in a hexagonal planar geometry to six equivalent O2- atoms. All Na–O bond lengths are 2.54 Å. U5+ is bonded to eight O2- atoms to form distorted UO8 hexagonal bipyramids that share edges with six equivalent TeO5 square pyramids. There are two shorter (1.85 Å) and six longer (2.44 Å) U–O bond lengths. Te+4.33+ is bonded to five O2- atoms to form distorted TeO5 square pyramids that share corners with six equivalent TeO5 square pyramids and an edgeedge with one UO8 hexagonal bipyramid. There are a spread of Te–O bond distances ranging from 1.93–2.32 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Na1+ and two equivalent Te+4.33+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one U5+ and two equivalent Te+4.33+ atoms. In the third O2- site, O2- is bonded in a single-bond geometry to one U5+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to three equivalent Te+4.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2UTeO7 by Materials Project

Na2UTeO7 crystallizes in the orthorhombic Ama2 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to seven O2- atoms to form distorted NaO7 pentagonal bipyramids that share corners with two equivalent TeO6 octahedra, edges with four equivalent NaO8 hexagonal bipyramids, and edges with two equivalent TeO6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Na–O bond distances ranging from 2.37–2.77 Å. In the second Na1+ site, Na1+ is bonded to eight O2- atoms to form distorted NaO8 hexagonal bipyramids that share edges with two equivalent NaO8 hexagonal bipyramids, edges with two equivalent TeO6 octahedra, and edges with four equivalent NaO7 pentagonal bipyramids. There are a spread of Na–O bond distances ranging from 2.47–2.89 Å. U6+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of U–O bond distances ranging from 1.87–2.58 Å. Te6+ is bonded to six O2- atoms to form TeO6 octahedra that share corners with two equivalent TeO6 octahedra, corners with two equivalent NaO7 pentagonal bipyramids, edges with two equivalent NaO8 hexagonal bipyramids, and edges with two equivalent NaO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 33°. There are a spread of Te–O bond distances ranging from 1.92–1.99 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one U6+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one U6+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one U6+, and one Te6+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+, one U6+, and two equivalent Te6+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Na1+, one U6+, and one Te6+ atom.

36 MATERIALS SCIENCE↗