Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Na2U2O7”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

2 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Na2U2O7 by Materials Project

Na2U2O7 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Na–O bond distances ranging from 2.46–2.75 Å. In the second Na1+ site, Na1+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.61–2.82 Å. There are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of U–O bond distances ranging from 1.87–2.50 Å. In the second U6+ site, U6+ is bonded to six O2- atoms to form distorted corner-sharing UO6 octahedra. The corner-sharing octahedral tilt angles are 43°. There are a spread of U–O bond distances ranging from 1.90–2.26 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-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 to three Na1+ and one U6+ atom to form distorted corner-sharing ONa3U tetrahedra. In the fourth O2- site, O2- is bonded to three Na1+ and one U6+ atom to form distorted corner-sharing ONa3U tetrahedra. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three U6+ atoms. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three U6+ atoms. In the seventh O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three U6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2U2O7 by Materials Project

Na2U2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.37–2.84 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with four equivalent UO6 octahedra and corners with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 54°. There are four shorter (2.41 Å) and two longer (2.87 Å) Na–O bond lengths. In the third Na1+ site, Na1+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.47–3.00 Å. There are two inequivalent U6+ sites. In the first U6+ site, U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with two equivalent UO6 octahedra, corners with two equivalent UO7 pentagonal bipyramids, and edges with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of U–O bond distances ranging from 1.90–2.21 Å. In the second U6+ site, U6+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share a cornercorner with one NaO6 octahedra, corners with two equivalent UO6 octahedra, edges with two equivalent UO6 octahedra, and edges with two equivalent UO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 36–64°. There are a spread of U–O bond distances ranging from 1.87–2.59 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Na1+ and three U6+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and three U6+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Na1+ and one U6+ atom. In the fourth O2- site, O2- is bonded to three Na1+ and one U6+ atom to form a mixture of distorted edge and corner-sharing ONa3U tetrahedra. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+ and one U6+ atom.

36 MATERIALS SCIENCE↗