UOs2Zn20 crystallizes in the cubic Fd-3m space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Zn(1) and twelve equivalent Zn(3) atoms. Os(1) is bonded to six equivalent Zn(2) and six equivalent Zn(3) atoms to form OsZn12 cuboctahedra that share corners with six equivalent Os(1)Zn12 cuboctahedra, edges with eighteen equivalent Zn(3)UZn10Os cuboctahedra, and faces with six equivalent Zn(3)UZn10Os cuboctahedra. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 14-coordinate geometry to two equivalent U(1) and twelve equivalent Zn(3) atoms. In the second Zn site, Zn(2) is bonded in a distorted linear geometry to two equivalent Os(1) and six equivalent Zn(3) atoms. In the third Zn site, Zn(3) is bonded to one U(1), one Os(1), two equivalent Zn(1), three equivalent Zn(2), and five equivalent Zn(3) atoms to form distorted ZnUZn10Os cuboctahedra that share corners with fifteen equivalent Zn(3)UZn10Os cuboctahedra, edges with two equivalent Zn(3)UZn10Os cuboctahedra, edges with three equivalent Os(1)Zn12 cuboctahedra,  a faceface with one Os(1)Zn12 cuboctahedra, and faces with fifteen equivalent Zn(3)UZn10Os cuboctahedra.
UOs2Zn20 crystallizes in the cubic Fd-3m space group. U(1) is bonded in a 16-coordinate geometry to four equivalent Zn(1) and twelve equivalent Zn(3) atoms. All U(1)-Zn(1) bond lengths are 3.10 Å. All U(1)-Zn(3) bond lengths are 3.13 Å. Os(1) is bonded to six equivalent Zn(2) and six equivalent Zn(3) atoms to form OsZn12 cuboctahedra that share corners with six equivalent Os(1)Zn12 cuboctahedra, edges with eighteen equivalent Zn(3)UZn10Os cuboctahedra, and faces with six equivalent Zn(3)UZn10Os cuboctahedra. All Os(1)-Zn(2) bond lengths are 2.54 Å. All Os(1)-Zn(3) bond lengths are 2.81 Å. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 14-coordinate geometry to two equivalent U(1) and twelve equivalent Zn(3) atoms. All Zn(1)-Zn(3) bond lengths are 3.04 Å. In the second Zn site, Zn(2) is bonded in a distorted linear geometry to two equivalent Os(1) and six equivalent Zn(3) atoms. There are two shorter (2.69 Å) and four longer (2.83 Å) Zn(2)-Zn(3) bond lengths. In the third Zn site, Zn(3) is bonded to one U(1), one Os(1), two equivalent Zn(1), three equivalent Zn(2), and five equivalent Zn(3) atoms to form distorted ZnUZn10Os cuboctahedra that share corners with fifteen equivalent Zn(3)UZn10Os cuboctahedra, edges with two equivalent Zn(3)UZn10Os cuboctahedra, edges with three equivalent Os(1)Zn12 cuboctahedra,  a faceface with one Os(1)Zn12 cuboctahedra, and faces with fifteen equivalent Zn(3)UZn10Os cuboctahedra. There are a spread of Zn(3)-Zn(3) bond distances ranging from 2.64-2.92 Å.