Y5Ni2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to four equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted YNi4Bi2 octahedra that share corners with six equivalent Y(1)Ni4Bi2 octahedra, corners with sixteen equivalent Y(2)Ni3Bi2 trigonal bipyramids, and faces with eight equivalent Y(2)Ni3Bi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-51°. In the second Y site, Y(2) is bonded to three equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted YNi3Bi2 trigonal bipyramids that share corners with four equivalent Y(1)Ni4Bi2 octahedra, corners with twelve equivalent Y(2)Ni3Bi2 trigonal bipyramids, edges with seven equivalent Y(2)Ni3Bi2 trigonal bipyramids, faces with two equivalent Y(1)Ni4Bi2 octahedra, and  a faceface with one Y(2)Ni3Bi2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-62°. Ni(1) is bonded in a 8-coordinate geometry to two equivalent Y(1) and six equivalent Y(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Y(1) and eight equivalent Y(2) atoms.
Y5Ni2Bi crystallizes in the tetragonal I4/mcm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded to four equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted YNi4Bi2 octahedra that share corners with six equivalent Y(1)Ni4Bi2 octahedra, corners with sixteen equivalent Y(2)Ni3Bi2 trigonal bipyramids, and faces with eight equivalent Y(2)Ni3Bi2 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 0-51°. All Y(1)-Ni(1) bond lengths are 3.02 Å. Both Y(1)-Bi(1) bond lengths are 3.41 Å. In the second Y site, Y(2) is bonded to three equivalent Ni(1) and two equivalent Bi(1) atoms to form distorted YNi3Bi2 trigonal bipyramids that share corners with four equivalent Y(1)Ni4Bi2 octahedra, corners with twelve equivalent Y(2)Ni3Bi2 trigonal bipyramids, edges with seven equivalent Y(2)Ni3Bi2 trigonal bipyramids, faces with two equivalent Y(1)Ni4Bi2 octahedra, and  a faceface with one Y(2)Ni3Bi2 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-62°. There are two shorter (2.90 Å) and one longer (2.98 Å) Y(2)-Ni(1) bond length. Both Y(2)-Bi(1) bond lengths are 3.31 Å. Ni(1) is bonded in a 8-coordinate geometry to two equivalent Y(1) and six equivalent Y(2) atoms. Bi(1) is bonded in a distorted q6 geometry to two equivalent Y(1) and eight equivalent Y(2) atoms.