Materials Data on UCrNi by Materials Project

Abstract

UCrNi crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. U is bonded in a 12-coordinate geometry to four equivalent U, six equivalent Cr, and six equivalent Ni atoms. There are two shorter (3.05 Å) and two longer (3.11 Å) U–U bond lengths. There are four shorter (2.89 Å) and two longer (3.04 Å) U–Cr bond lengths. There are four shorter (2.88 Å) and two longer (3.08 Å) U–Ni bond lengths. Cr is bonded to six equivalent U, two equivalent Cr, and four equivalent Ni atoms to form distorted CrU6Cr2Ni4 cuboctahedra that share corners with eight equivalent NiU6Cr4Ni2 cuboctahedra, corners with ten equivalent CrU6Cr2Ni4 cuboctahedra, edges with six equivalent CrU6Cr2Ni4 cuboctahedra, faces with six equivalent CrU6Cr2Ni4 cuboctahedra, and faces with twelve equivalent NiU6Cr4Ni2 cuboctahedra. Both Cr–Cr bond lengths are 2.45 Å. All Cr–Ni bond lengths are 2.55 Å. Ni is bonded to six equivalent U, four equivalent Cr, and two equivalent Ni atoms to form NiU6Cr4Ni2 cuboctahedra that share corners with eight equivalent CrU6Cr2Ni4 cuboctahedra, corners with ten equivalent NiU6Cr4Ni2 cuboctahedra, edges with six equivalent NiU6Cr4Ni2 cuboctahedra, faces with six equivalent NiU6Cr4Ni2 cuboctahedra, and faces with twelve equivalent CrU6Cr2Ni4 cuboctahedra. Both Ni–Ni bond lengths are 2.44 Å.