ThY crystallizes in the trigonal R-3m space group. Th(1) is bonded to six equivalent Th(1) and six equivalent Y(1) atoms to form ThY6Th6 cuboctahedra that share corners with twelve equivalent Th(1)Y6Th6 cuboctahedra, edges with twelve equivalent Th(1)Y6Th6 cuboctahedra, edges with twelve equivalent Y(1)Y6Th6 cuboctahedra, faces with six equivalent Th(1)Y6Th6 cuboctahedra, and faces with twelve equivalent Y(1)Y6Th6 cuboctahedra. Y(1) is bonded to six equivalent Th(1) and six equivalent Y(1) atoms to form YY6Th6 cuboctahedra that share corners with twelve equivalent Y(1)Y6Th6 cuboctahedra, edges with twelve equivalent Th(1)Y6Th6 cuboctahedra, edges with twelve equivalent Y(1)Y6Th6 cuboctahedra, faces with six equivalent Y(1)Y6Th6 cuboctahedra, and faces with twelve equivalent Th(1)Y6Th6 cuboctahedra.
ThY crystallizes in the trigonal R-3m space group. Th(1) is bonded to six equivalent Th(1) and six equivalent Y(1) atoms to form ThY6Th6 cuboctahedra that share corners with twelve equivalent Th(1)Y6Th6 cuboctahedra, edges with twelve equivalent Th(1)Y6Th6 cuboctahedra, edges with twelve equivalent Y(1)Y6Th6 cuboctahedra, faces with six equivalent Th(1)Y6Th6 cuboctahedra, and faces with twelve equivalent Y(1)Y6Th6 cuboctahedra. All Th(1)-Th(1) bond lengths are 3.60 Å. All Th(1)-Y(1) bond lengths are 3.55 Å. Y(1) is bonded to six equivalent Th(1) and six equivalent Y(1) atoms to form YY6Th6 cuboctahedra that share corners with twelve equivalent Y(1)Y6Th6 cuboctahedra, edges with twelve equivalent Th(1)Y6Th6 cuboctahedra, edges with twelve equivalent Y(1)Y6Th6 cuboctahedra, faces with six equivalent Y(1)Y6Th6 cuboctahedra, and faces with twelve equivalent Th(1)Y6Th6 cuboctahedra. All Y(1)-Y(1) bond lengths are 3.60 Å.