DOE OSTI2020
UYCo10 crystallizes in the orthorhombic Pmmm space group. The structure is three-dimensional. U is bonded in a distorted hexagonal planar geometry to eighteen Co atoms. There are a spread of U–Co bond distances ranging from 2.63–3.14 Å. Y is bonded in a 6-coordinate geometry to eighteen Co atoms. There are a spread of Y–Co bond distances ranging from 2.87–3.14 Å. There are five inequivalent Co sites. In the first Co site, Co is bonded in a 12-coordinate geometry to one U, two equivalent Y, and eight Co atoms. There are a spread of Co–Co bond distances ranging from 2.40–2.77 Å. In the second Co site, Co is bonded to two equivalent U, one Y, and nine Co atoms to form a mixture of distorted face, edge, and corner-sharing CoYU2Co9 cuboctahedra. There are a spread of Co–Co bond distances ranging from 2.37–2.57 Å. In the third Co site, Co is bonded to four equivalent U and eight Co atoms to form CoU4Co8 cuboctahedra that share corners with twenty-four CoY2U2Co8 cuboctahedra, edges with ten CoY2U2Co8 cuboctahedra, and faces with fourteen CoYU2Co9 cuboctahedra. All Co–Co bond lengths are 2.41 Å. In the fourth Co site, Co is bonded to four equivalent Y and eight Co atoms to form CoY4Co8 cuboctahedra that share corners with sixteen CoY2U2Co8 cuboctahedra, edges with ten CoY2U2Co8 cuboctahedra, and faces with eighteen CoYU2Co9 cuboctahedra. All Co–Co bond lengths are 2.42 Å. In the fifth Co site, Co is bonded to two equivalent U, two equivalent Y, and eight Co atoms to form CoY2U2Co8 cuboctahedra that share corners with twenty CoYU2Co9 cuboctahedra, edges with ten CoY2U2Co8 cuboctahedra, and faces with sixteen CoYU2Co9 cuboctahedra. There are one shorter (2.39 Å) and one longer (2.45 Å) Co–Co bond lengths.