SEARCH · Engineering Papers
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.
VBr3 crystallizes in the hexagonal P6_3/mmc space group. The structure is one-dimensional and consists of two VBr3 ribbons oriented in the (0, 0, 1) direction. V3+ is bonded to six equivalent Br1- atoms to form distorted face-sharing VBr6 pentagonal pyramids. All V–Br bond lengths are 2.56 Å. Br1- is bonded in an L-shaped geometry to two equivalent V3+ atoms.
VBr2 is trigonal omega structured and crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one VBr2 sheet oriented in the (0, 0, 1) direction. V2+ is bonded to six equivalent Br1- atoms to form edge-sharing VBr6 octahedra. All V–Br bond lengths are 2.65 Å. Br1- is bonded in a distorted T-shaped geometry to three equivalent V2+ atoms.
V3Br crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent V sites. In the first V site, V is bonded to eight V and four equivalent Br atoms to form distorted VV8Br4 cuboctahedra that share corners with twelve equivalent VV8Br4 cuboctahedra, edges with eight equivalent VV8Br4 cuboctahedra, edges with eight equivalent BrV12 cuboctahedra, faces with four equivalent BrV12 cuboctahedra, and faces with ten equivalent VV8Br4 cuboctahedra. There are four shorter (2.51 Å) and four longer (2.89 Å) V–V bond lengths. All V–Br bond lengths are 2.89 Å. In the second V site, V is bonded in a square co-planar geometry to eight equivalent V and four equivalent Br atoms. All V–Br bond lengths are 2.51 Å. Br is bonded to twelve V atoms to form distorted BrV12 cuboctahedra that share corners with four equivalent BrV12 cuboctahedra, edges with eight equivalent BrV12 cuboctahedra, edges with sixteen equivalent VV8Br4 cuboctahedra, faces with four equivalent BrV12 cuboctahedra, and faces with eight equivalent VV8Br4 cuboctahedra.