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5 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on UWC2 by Materials Project

UWC2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. U6+ is bonded in a 6-coordinate geometry to six C4- atoms. There are a spread of U–C bond distances ranging from 2.32–2.68 Å. W2+ is bonded in a 3-coordinate geometry to five C4- atoms. There are a spread of W–C bond distances ranging from 2.08–2.39 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to three equivalent U6+, two equivalent W2+, and one C4- atom to form a mixture of distorted edge and corner-sharing CU3W2C octahedra. The corner-sharing octahedra tilt angles range from 16–22°. The C–C bond length is 1.51 Å. In the second C4- site, C4- is bonded in a 5-coordinate geometry to three equivalent U6+, three equivalent W2+, and one C4- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on UWC2 by Materials Project

UWC2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. U6+ is bonded to seven C4- atoms to form distorted UC7 pentagonal bipyramids that share corners with four equivalent UC7 pentagonal bipyramids, corners with three equivalent WC5 trigonal bipyramids, edges with four equivalent UC7 pentagonal bipyramids, edges with seven equivalent WC5 trigonal bipyramids, and faces with two equivalent UC7 pentagonal bipyramids. There are a spread of U–C bond distances ranging from 2.39–2.52 Å. W2+ is bonded to five C4- atoms to form WC5 trigonal bipyramids that share corners with three equivalent UC7 pentagonal bipyramids, corners with four equivalent WC5 trigonal bipyramids, edges with seven equivalent UC7 pentagonal bipyramids, and edges with two equivalent WC5 trigonal bipyramids. There are a spread of W–C bond distances ranging from 2.14–2.22 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to four equivalent U6+ and two equivalent W2+ atoms to form a mixture of corner, edge, and face-sharing CU4W2 octahedra. The corner-sharing octahedra tilt angles range from 14–58°. In the second C4- site, C4- is bonded to three equivalent U6+ and three equivalent W2+ atoms to form a mixture of corner, edge, and face-sharing CU3W3 octahedra. The corner-sharing octahedra tilt angles range from 14–58°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U(WC)4 by Materials Project

UW4C4 crystallizes in the tetragonal P4/m space group. The structure is three-dimensional. there are two inequivalent U4+ sites. In the first U4+ site, U4+ is bonded in a body-centered cubic geometry to eight equivalent C4- atoms. All U–C bond lengths are 2.57 Å. In the second U4+ site, U4+ is bonded in a body-centered cubic geometry to eight equivalent C4- atoms. All U–C bond lengths are 2.50 Å. There are two inequivalent W3+ sites. In the first W3+ site, W3+ is bonded in a rectangular see-saw-like geometry to four C4- atoms. There are a spread of W–C bond distances ranging from 2.15–2.19 Å. In the second W3+ site, W3+ is bonded to four C4- atoms to form corner-sharing WC4 trigonal pyramids. There are a spread of W–C bond distances ranging from 2.08–2.11 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to two equivalent U4+ and four W3+ atoms to form a mixture of corner, edge, and face-sharing CU2W4 octahedra. The corner-sharing octahedra tilt angles range from 0–68°. In the second C4- site, C4- is bonded to two equivalent U4+ and four W3+ atoms to form a mixture of corner, edge, and face-sharing CU2W4 octahedra. The corner-sharing octahedra tilt angles range from 0–67°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U2W2C3 by Materials Project

U2W2C3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. U4+ is bonded in a pentagonal planar geometry to five C4- atoms. There are three shorter (2.44 Å) and two longer (2.49 Å) U–C bond lengths. W2+ is bonded to four C4- atoms to form a mixture of corner and edge-sharing WC4 trigonal pyramids. There are a spread of W–C bond distances ranging from 2.09–2.19 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to three equivalent U4+ and three equivalent W2+ atoms to form CU3W3 octahedra that share corners with six equivalent CU4W2 octahedra, edges with six equivalent CU3W3 octahedra, and a faceface with one CU4W2 octahedra. The corner-sharing octahedra tilt angles range from 40–60°. In the second C4- site, C4- is bonded to four equivalent U4+ and two equivalent W2+ atoms to form CU4W2 octahedra that share corners with twelve equivalent CU3W3 octahedra, edges with two equivalent CU4W2 octahedra, and faces with two equivalent CU3W3 octahedra. The corner-sharing octahedra tilt angles range from 40–60°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U(WC)4 by Materials Project

UW4C4 crystallizes in the tetragonal P4/m space group. The structure is three-dimensional. there are two inequivalent U4+ sites. In the first U4+ site, U4+ is bonded in a body-centered cubic geometry to eight equivalent C4- atoms. All U–C bond lengths are 2.49 Å. In the second U4+ site, U4+ is bonded in a body-centered cubic geometry to eight equivalent C4- atoms. All U–C bond lengths are 2.53 Å. There are two inequivalent W3+ sites. In the first W3+ site, W3+ is bonded to four C4- atoms to form corner-sharing WC4 trigonal pyramids. There are one shorter (2.09 Å) and three longer (2.11 Å) W–C bond lengths. In the second W3+ site, W3+ is bonded in a rectangular see-saw-like geometry to four C4- atoms. There are a spread of W–C bond distances ranging from 2.13–2.16 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to two equivalent U4+ and four W3+ atoms to form a mixture of edge, face, and corner-sharing CU2W4 octahedra. The corner-sharing octahedra tilt angles range from 0–67°. In the second C4- site, C4- is bonded to two equivalent U4+ and four W3+ atoms to form a mixture of edge, face, and corner-sharing CU2W4 octahedra. The corner-sharing octahedra tilt angles range from 0–68°.

36 MATERIALS SCIENCE↗