Materials Data on U2CrN3 by Materials Project
U2CrN3 crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. U3+ is bonded to seven N3- atoms to form a mixture of distorted corner, edge, and face-sharing UN7 pentagonal bipyramids. There are a spread of U–N bond distances ranging from 2.27–2.50 Å. Cr3+ is bonded in a square co-planar geometry to four N3- atoms. There is two shorter (1.85 Å) and two longer (2.06 Å) Cr–N bond length. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to four equivalent U3+ and two equivalent Cr3+ atoms to form NU4Cr2 octahedra that share corners with fourteen NU4Cr2 octahedra, edges with two equivalent NU4Cr2 octahedra, and faces with four equivalent NU5Cr octahedra. The corner-sharing octahedra tilt angles range from 0–58°. In the second N3- site, N3- is bonded to five equivalent U3+ and one Cr3+ atom to form distorted NU5Cr octahedra that share corners with eleven NU4Cr2 octahedra, edges with eight equivalent NU5Cr octahedra, and faces with two equivalent NU4Cr2 octahedra. The corner-sharing octahedra tilt angles range from 0–58°.