Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Na-Se-Sn”

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.

4 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Na2Sn2Se5 by Materials Project

Na2Sn2Se5 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to seven Se2- atoms to form distorted NaSe7 pentagonal bipyramids that share corners with four equivalent NaSe7 pentagonal bipyramids, corners with three equivalent SnSe4 tetrahedra, edges with two equivalent NaSe6 octahedra, an edgeedge with one SnSe4 tetrahedra, and faces with two equivalent NaSe6 octahedra. There are a spread of Na–Se bond distances ranging from 3.10–3.45 Å. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with four equivalent NaSe6 octahedra, corners with four equivalent SnSe4 tetrahedra, edges with two equivalent NaSe7 pentagonal bipyramids, and faces with two equivalent NaSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 15–27°. There are a spread of Na–Se bond distances ranging from 3.05–3.29 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with four equivalent NaSe6 octahedra, corners with three equivalent NaSe7 pentagonal bipyramids, and an edgeedge with one NaSe7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 38–89°. There are a spread of Sn–Se bond distances ranging from 2.49–2.60 Å. In the second Sn4+ site, Sn4+ is bonded in a distorted rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Sn–Se bond distances ranging from 2.50–2.61 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 4-coordinate geometry to two Na1+ and two Sn4+ atoms. In the second Se2- site, Se2- is bonded to four Na1+ and one Sn4+ atom to form distorted SeNa4Sn trigonal bipyramids that share corners with four equivalent SeNa4Sn trigonal bipyramids, corners with three equivalent SeNa2Sn2 trigonal pyramids, and an edgeedge with one SeNa2Sn2 trigonal pyramid. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to four Na1+ and one Sn4+ atom. In the fourth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Na1+ and two Sn4+ atoms. In the fifth Se2- site, Se2- is bonded to two Na1+ and two Sn4+ atoms to form a mixture of distorted edge and corner-sharing SeNa2Sn2 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na6Sn2Se7 by Materials Project

Na6Sn2Se7 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to four Se2- atoms. There are two shorter (2.91 Å) and two longer (2.97 Å) Na–Se bond lengths. In the second Na1+ site, Na1+ is bonded to six Se2- atoms to form distorted NaSe6 octahedra that share corners with two NaSe6 octahedra, a cornercorner with one SnSe4 tetrahedra, edges with four NaSe6 octahedra, and edges with three equivalent SnSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 11–37°. There are a spread of Na–Se bond distances ranging from 3.04–3.52 Å. In the third Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Na–Se bond distances ranging from 3.02–3.56 Å. In the fourth Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with two equivalent NaSe6 octahedra, corners with two equivalent SnSe4 tetrahedra, edges with four equivalent NaSe6 octahedra, and edges with two equivalent SnSe4 tetrahedra. The corner-sharing octahedral tilt angles are 11°. There are a spread of Na–Se bond distances ranging from 2.96–3.26 Å. Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with two NaSe6 octahedra, a cornercorner with one SnSe4 tetrahedra, and edges with four NaSe6 octahedra. The corner-sharing octahedra tilt angles range from 22–59°. There are a spread of Sn–Se bond distances ranging from 2.53–2.60 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to five Na1+ and one Sn4+ atom to form a mixture of distorted corner and edge-sharing SeNa5Sn octahedra. The corner-sharing octahedra tilt angles range from 0–74°. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to four Na1+ and two equivalent Sn4+ atoms. In the third Se2- site, Se2- is bonded in a 6-coordinate geometry to five Na1+ and one Sn4+ atom. In the fourth Se2- site, Se2- is bonded to five Na1+ and one Sn4+ atom to form a mixture of corner and edge-sharing SeNa5Sn octahedra. The corner-sharing octahedra tilt angles range from 0–8°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na4SnSe4 by Materials Project

Na4SnSe4 crystallizes in the tetragonal P-42_1c space group. The structure is three-dimensional. Na1+ is bonded to five equivalent Se2- atoms to form NaSe5 trigonal bipyramids that share corners with three equivalent SnSe4 tetrahedra, corners with ten equivalent NaSe5 trigonal bipyramids, an edgeedge with one SnSe4 tetrahedra, and edges with five equivalent NaSe5 trigonal bipyramids. There are a spread of Na–Se bond distances ranging from 2.95–3.27 Å. Sn4+ is bonded to four equivalent Se2- atoms to form SnSe4 tetrahedra that share corners with twelve equivalent NaSe5 trigonal bipyramids and edges with four equivalent NaSe5 trigonal bipyramids. All Sn–Se bond lengths are 2.57 Å. Se2- is bonded in a 6-coordinate geometry to five equivalent Na1+ and one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2SnSe3 by Materials Project

Na2SnSe3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six Se2- atoms to form NaSe6 octahedra that share corners with two equivalent NaSe6 octahedra, corners with three equivalent SnSe4 tetrahedra, corners with six equivalent NaSe5 trigonal bipyramids, edges with three equivalent NaSe6 octahedra, edges with two equivalent SnSe4 tetrahedra, and edges with two equivalent NaSe5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 19°. There are a spread of Na–Se bond distances ranging from 2.98–3.27 Å. In the second Na1+ site, Na1+ is bonded to five Se2- atoms to form NaSe5 trigonal bipyramids that share corners with six equivalent NaSe6 octahedra, corners with two equivalent SnSe4 tetrahedra, corners with two equivalent NaSe5 trigonal bipyramids, edges with two equivalent NaSe6 octahedra, edges with two equivalent SnSe4 tetrahedra, and edges with two equivalent NaSe5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 16–89°. There are a spread of Na–Se bond distances ranging from 3.02–3.20 Å. Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with three equivalent NaSe6 octahedra, corners with two equivalent SnSe4 tetrahedra, corners with two equivalent NaSe5 trigonal bipyramids, edges with two equivalent NaSe6 octahedra, and edges with two equivalent NaSe5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 25–68°. There are a spread of Sn–Se bond distances ranging from 2.52–2.62 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to five Na1+ and one Sn4+ atom to form distorted SeNa5Sn pentagonal pyramids that share corners with two equivalent SeNa5Sn pentagonal pyramids, corners with four equivalent SeNa4Sn trigonal bipyramids, corners with three equivalent SeNa2Sn2 trigonal pyramids, edges with three equivalent SeNa5Sn pentagonal pyramids, edges with three equivalent SeNa4Sn trigonal bipyramids, and edges with two equivalent SeNa2Sn2 trigonal pyramids. In the second Se2- site, Se2- is bonded to four Na1+ and one Sn4+ atom to form distorted SeNa4Sn trigonal bipyramids that share corners with four equivalent SeNa5Sn pentagonal pyramids, corners with two equivalent SeNa4Sn trigonal bipyramids, corners with four equivalent SeNa2Sn2 trigonal pyramids, edges with three equivalent SeNa5Sn pentagonal pyramids, edges with two equivalent SeNa4Sn trigonal bipyramids, and an edgeedge with one SeNa2Sn2 trigonal pyramid. In the third Se2- site, Se2- is bonded to two Na1+ and two equivalent Sn4+ atoms to form distorted SeNa2Sn2 trigonal pyramids that share corners with three equivalent SeNa5Sn pentagonal pyramids, corners with four equivalent SeNa4Sn trigonal bipyramids, corners with two equivalent SeNa2Sn2 trigonal pyramids, edges with two equivalent SeNa5Sn pentagonal pyramids, and an edgeedge with one SeNa4Sn trigonal bipyramid.

36 MATERIALS SCIENCE↗