Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Na(VSe2)2”

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.

3 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Na(VSe2)2 by Materials Project

Na(VSe2)2 is MAX Phase-like structured and crystallizes in the trigonal R3m space group. The structure is two-dimensional and consists of three Na(VSe2)2 sheets oriented in the (0, 0, 1) direction. Na1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are three shorter (2.99 Å) and three longer (3.00 Å) Na–Se bond lengths. There are two inequivalent V+3.50+ sites. In the first V+3.50+ site, V+3.50+ is bonded to six Se2- atoms to form edge-sharing VSe6 octahedra. There are three shorter (2.52 Å) and three longer (2.59 Å) V–Se bond lengths. In the second V+3.50+ site, V+3.50+ is bonded to six Se2- atoms to form edge-sharing VSe6 octahedra. There are three shorter (2.52 Å) and three longer (2.59 Å) V–Se bond lengths. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three equivalent Na1+ and three equivalent V+3.50+ atoms to form a mixture of face, edge, and corner-sharing SeNa3V3 octahedra. In the second Se2- site, Se2- is bonded in a distorted T-shaped geometry to three equivalent V+3.50+ atoms. In the third Se2- site, Se2- is bonded to three equivalent Na1+ and three equivalent V+3.50+ atoms to form a mixture of distorted face, edge, and corner-sharing SeNa3V3 pentagonal pyramids. The corner-sharing octahedral tilt angles are 41°. In the fourth Se2- site, Se2- is bonded in a distorted T-shaped geometry to three equivalent V+3.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na(VSe2)2 by Materials Project

Na(VSe2)2 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to six Se2- atoms. There are a spread of Na–Se bond distances ranging from 2.98–3.10 Å. There are two inequivalent V+3.50+ sites. In the first V+3.50+ site, V+3.50+ is bonded to six Se2- atoms to form edge-sharing VSe6 octahedra. There are a spread of V–Se bond distances ranging from 2.48–2.59 Å. In the second V+3.50+ site, V+3.50+ is bonded to six Se2- atoms to form edge-sharing VSe6 octahedra. There are a spread of V–Se bond distances ranging from 2.47–2.59 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to two equivalent Na1+ and three V+3.50+ atoms to form distorted SeNa2V3 square pyramids that share corners with five equivalent SeNa2V3 trigonal bipyramids, corners with four SeNaV3 trigonal pyramids, edges with two equivalent SeNa2V3 square pyramids, edges with two equivalent SeNa2V3 trigonal bipyramids, and edges with four SeNaV3 trigonal pyramids. In the second Se2- site, Se2- is bonded to one Na1+ and three V+3.50+ atoms to form distorted SeNaV3 trigonal pyramids that share corners with two equivalent SeNa2V3 square pyramids, corners with two equivalent SeNa2V3 trigonal bipyramids, corners with six SeNaV3 trigonal pyramids, edges with two equivalent SeNa2V3 square pyramids, edges with two equivalent SeNa2V3 trigonal bipyramids, and an edgeedge with one SeNaV3 trigonal pyramid. In the third Se2- site, Se2- is bonded to two equivalent Na1+ and three V+3.50+ atoms to form distorted SeNa2V3 trigonal bipyramids that share corners with five equivalent SeNa2V3 square pyramids, corners with four SeNaV3 trigonal pyramids, edges with two equivalent SeNa2V3 square pyramids, edges with two equivalent SeNa2V3 trigonal bipyramids, and edges with four SeNaV3 trigonal pyramids. In the fourth Se2- site, Se2- is bonded to one Na1+ and three V+3.50+ atoms to form distorted SeNaV3 trigonal pyramids that share corners with two equivalent SeNa2V3 square pyramids, corners with two equivalent SeNa2V3 trigonal bipyramids, corners with six SeNaV3 trigonal pyramids, edges with two equivalent SeNa2V3 square pyramids, edges with two equivalent SeNa2V3 trigonal bipyramids, and an edgeedge with one SeNaV3 trigonal pyramid.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2V3(SeO)6 by Materials Project

(NaO3)2(VSe2)3 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one NaO3 sheet oriented in the (0, 0, 1) direction and one VSe2 sheet oriented in the (0, 0, 1) direction. In the NaO3 sheet, Na1+ is bonded in a distorted rectangular see-saw-like geometry to four equivalent O2- atoms. There are two shorter (2.24 Å) and two longer (2.26 Å) Na–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one O2- atom. The O–O bond length is 1.35 Å. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent O2- atoms. In the VSe2 sheet, there are two inequivalent V+4.67+ sites. In the first V+4.67+ site, V+4.67+ is bonded to six Se+0.67- atoms to form edge-sharing VSe6 octahedra. There are two shorter (2.55 Å) and four longer (2.58 Å) V–Se bond lengths. In the second V+4.67+ site, V+4.67+ is bonded to six Se+0.67- atoms to form edge-sharing VSe6 octahedra. There are four shorter (2.58 Å) and two longer (2.60 Å) V–Se bond lengths. There are two inequivalent Se+0.67- sites. In the first Se+0.67- site, Se+0.67- is bonded in a 3-coordinate geometry to three V+4.67+ atoms. In the second Se+0.67- site, Se+0.67- is bonded in a 4-coordinate geometry to three V+4.67+ atoms.

36 MATERIALS SCIENCE↗