Materials Data on UCrC2 by Materials Project
UCrC2 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. U5+ is bonded to six C4- atoms to form distorted UC6 octahedra that share corners with three equivalent CU3Cr3C hexagonal pyramids, corners with four equivalent UC6 octahedra, and edges with four equivalent UC6 octahedra. The corner-sharing octahedra tilt angles range from 9–83°. There are a spread of U–C bond distances ranging from 2.37–2.65 Å. Cr3+ is bonded in a 6-coordinate geometry to six C4- atoms. There are a spread of Cr–C bond distances ranging from 1.95–2.28 Å. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to three equivalent U5+, three equivalent Cr3+, and one C4- atom to form distorted CU3Cr3C hexagonal pyramids that share corners with three equivalent UC6 octahedra and edges with six equivalent CU3Cr3C hexagonal pyramids. The corner-sharing octahedra tilt angles range from 32–118°. The C–C bond length is 1.53 Å. In the second C4- site, C4- is bonded in a 7-coordinate geometry to three equivalent U5+, three equivalent Cr3+, and one C4- atom.