Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Br-Na-O-W”

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.

Materials Data on NaW2(Br3O)2 by Materials Project

NaW2(OBr3)2 crystallizes in the monoclinic Cm space group. The structure is two-dimensional and consists of two NaW2(OBr3)2 sheets oriented in the (1, 0, 0) direction. Na1+ is bonded in a body-centered cubic geometry to eight Br1- atoms. There are a spread of Na–Br bond distances ranging from 3.20–3.30 Å. There are two inequivalent W+4.50+ sites. In the first W+4.50+ site, W+4.50+ is bonded to two equivalent O2- and four Br1- atoms to form a mixture of distorted edge and corner-sharing WBr4O2 octahedra. The corner-sharing octahedral tilt angles are 3°. Both W–O bond lengths are 1.94 Å. There are a spread of W–Br bond distances ranging from 2.54–2.71 Å. In the second W+4.50+ site, W+4.50+ is bonded to two equivalent O2- and four Br1- atoms to form a mixture of distorted edge and corner-sharing WBr4O2 octahedra. The corner-sharing octahedral tilt angles are 3°. Both W–O bond lengths are 1.94 Å. There are a spread of W–Br bond distances ranging from 2.54–2.71 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two equivalent W+4.50+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent W+4.50+ atoms. There are six inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the second Br1- site, Br1- is bonded in a distorted L-shaped geometry to two W+4.50+ atoms. In the third Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the fourth Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the fifth Br1- site, Br1- is bonded in a 3-coordinate geometry to two equivalent Na1+ and one W+4.50+ atom. In the sixth Br1- site, Br1- is bonded in a distorted L-shaped geometry to two W+4.50+ atoms.

36 MATERIALS SCIENCE↗