Materials Data on U(CuAs)2 by Materials Project
U(CuAs)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. U4+ is bonded to six equivalent As3- atoms to form UAs6 octahedra that share corners with twelve equivalent CuAs4 tetrahedra, edges with six equivalent UAs6 octahedra, and edges with six equivalent CuAs4 tetrahedra. All U–As bond lengths are 2.88 Å. Cu1+ is bonded to four equivalent As3- atoms to form CuAs4 tetrahedra that share corners with six equivalent UAs6 octahedra, corners with six equivalent CuAs4 tetrahedra, edges with three equivalent UAs6 octahedra, and edges with three equivalent CuAs4 tetrahedra. The corner-sharing octahedra tilt angles range from 18–55°. There are three shorter (2.45 Å) and one longer (2.50 Å) Cu–As bond lengths. As3- is bonded to three equivalent U4+ and four equivalent Cu1+ atoms to form a mixture of distorted corner and edge-sharing AsU3Cu4 pentagonal bipyramids.