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6 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Cr7C3 by Materials Project

Cr7C3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are five inequivalent Cr sites. In the first Cr site, Cr is bonded in a 3-coordinate geometry to three C atoms. There are a spread of Cr–C bond distances ranging from 2.01–2.04 Å. In the second Cr site, Cr is bonded in a distorted bent 150 degrees geometry to two C atoms. Both Cr–C bond lengths are 2.07 Å. In the third Cr site, Cr is bonded in a distorted trigonal planar geometry to three C atoms. There are one shorter (1.99 Å) and two longer (2.02 Å) Cr–C bond lengths. In the fourth Cr site, Cr is bonded in a distorted L-shaped geometry to two equivalent C atoms. Both Cr–C bond lengths are 2.07 Å. In the fifth Cr site, Cr is bonded in a 3-coordinate geometry to three C atoms. There are one shorter (1.99 Å) and two longer (2.04 Å) Cr–C bond lengths. There are two inequivalent C sites. In the first C site, C is bonded in a 6-coordinate geometry to six Cr atoms. In the second C site, C is bonded in a 6-coordinate geometry to six Cr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3C2 by Materials Project

Cr3C2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Cr+2.67+ sites. In the first Cr+2.67+ site, Cr+2.67+ is bonded in a 2-coordinate geometry to five C4- atoms. There are a spread of Cr–C bond distances ranging from 2.02–2.58 Å. In the second Cr+2.67+ site, Cr+2.67+ is bonded to five C4- atoms to form a mixture of distorted edge, face, and corner-sharing CrC5 trigonal bipyramids. There are a spread of Cr–C bond distances ranging from 2.00–2.11 Å. In the third Cr+2.67+ site, Cr+2.67+ is bonded to five C4- atoms to form a mixture of edge, face, and corner-sharing CrC5 square pyramids. There are a spread of Cr–C bond distances ranging from 2.02–2.09 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 6-coordinate geometry to eight Cr+2.67+ atoms. In the second C4- site, C4- is bonded in a 7-coordinate geometry to seven Cr+2.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr3C2 by Materials Project

Cr3C2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Cr+2.67+ sites. In the first Cr+2.67+ site, Cr+2.67+ is bonded to four C4- atoms to form corner-sharing CrC4 tetrahedra. There is two shorter (1.95 Å) and two longer (1.96 Å) Cr–C bond length. In the second Cr+2.67+ site, Cr+2.67+ is bonded in a 5-coordinate geometry to five C4- atoms. There are a spread of Cr–C bond distances ranging from 1.99–2.41 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded in a 6-coordinate geometry to eight Cr+2.67+ atoms. In the second C4- site, C4- is bonded to six Cr+2.67+ atoms to form a mixture of edge and corner-sharing CCr6 octahedra. The corner-sharing octahedral tilt angles are 56°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrC by Materials Project

CrC is Halite, Rock Salt structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Cr3+ is bonded to six equivalent C3- atoms to form a mixture of edge and corner-sharing CrC6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Cr–C bond lengths are 2.05 Å. C3- is bonded to six equivalent Cr3+ atoms to form a mixture of edge and corner-sharing CCr6 octahedra. The corner-sharing octahedral tilt angles are 0°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cr23C6 by Materials Project

Cr23C6 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are four inequivalent Cr sites. In the first Cr site, Cr is bonded in a cuboctahedral geometry to twelve equivalent Cr atoms. All Cr–Cr bond lengths are 2.53 Å. In the second Cr site, Cr is bonded in a distorted tetrahedral geometry to four equivalent Cr atoms. All Cr–Cr bond lengths are 2.40 Å. In the third Cr site, Cr is bonded in a distorted trigonal non-coplanar geometry to one Cr and three equivalent C atoms. All Cr–C bond lengths are 2.09 Å. In the fourth Cr site, Cr is bonded in a bent 150 degrees geometry to one Cr and two equivalent C atoms. Both Cr–C bond lengths are 2.12 Å. C is bonded in a 8-coordinate geometry to eight Cr atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CrC by Materials Project

CrC is Tungsten Carbide structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Cr3+ is bonded to six equivalent C3- atoms to form a mixture of distorted edge, face, and corner-sharing CrC6 pentagonal pyramids. All Cr–C bond lengths are 2.04 Å. C3- is bonded to six equivalent Cr3+ atoms to form a mixture of distorted edge, face, and corner-sharing CCr6 pentagonal pyramids.

36 MATERIALS SCIENCE↗