Materials Data on UCo3 by Materials Project
UCo3 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent U sites. In the first U site, U is bonded in a 12-coordinate geometry to twelve Co atoms. There are a spread of U–Co bond distances ranging from 2.78–3.01 Å. In the second U site, U is bonded in a distorted hexagonal planar geometry to eighteen Co atoms. There are six shorter (2.77 Å) and twelve longer (3.14 Å) U–Co bond lengths. There are three inequivalent Co sites. In the first Co site, Co is bonded to five U and seven Co atoms to form a mixture of distorted corner, edge, and face-sharing CoU5Co7 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.39–2.46 Å. In the second Co site, Co is bonded to three equivalent U and nine Co atoms to form distorted CoU3Co9 cuboctahedra that share corners with eighteen CoU5Co7 cuboctahedra, edges with six equivalent CoU3Co9 cuboctahedra, and faces with twenty-two CoU5Co7 cuboctahedra. All Co–Co bond lengths are 2.77 Å. In the third Co site, Co is bonded to six equivalent U and six equivalent Co atoms to form CoU6Co6 cuboctahedra that share corners with eighteen CoU5Co7 cuboctahedra, edges with six equivalent CoU6Co6 cuboctahedra, and faces with twenty CoU5Co7 cuboctahedra.