Ni6SbTe2 crystallizes in the tetragonal I4mm space group. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 10-coordinate geometry to two equivalent Ni(3), four equivalent Ni(1), two equivalent Sb(1), and two equivalent Te(1) atoms. In the second Ni site, Ni(2) is bonded to two equivalent Ni(3), two equivalent Ni(4), four equivalent Ni(2), two equivalent Sb(1), and two equivalent Te(2) atoms to form distorted NiNi8Sb2Te2 cuboctahedra that share corners with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, edges with four equivalent Ni(3)Ni8Sb4 cuboctahedra, edges with four equivalent Sb(1)Ni12 cuboctahedra, edges with four equivalent Te(2)Ni8 hexagonal bipyramids, faces with two equivalent Ni(3)Ni8Sb4 cuboctahedra, faces with two equivalent Sb(1)Ni12 cuboctahedra, faces with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, and faces with two equivalent Te(2)Ni8 hexagonal bipyramids. In the third Ni site, Ni(3) is bonded to four equivalent Ni(1), four equivalent Ni(2), and four equivalent Sb(1) atoms to form NiNi8Sb4 cuboctahedra that share corners with four equivalent Ni(3)Ni8Sb4 cuboctahedra, corners with four equivalent Te(2)Ni8 hexagonal bipyramids, edges with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, faces with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, faces with four equivalent Ni(3)Ni8Sb4 cuboctahedra, faces with four equivalent Sb(1)Ni12 cuboctahedra, and  a faceface with one Te(2)Ni8 hexagonal bipyramid. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to four equivalent Ni(2), one Te(1), and four equivalent Te(2) atoms. Sb(1) is bonded to four equivalent Ni(1), four equivalent Ni(2), and four equivalent Ni(3) atoms to form SbNi12 cuboctahedra that share corners with four equivalent Sb(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, edges with four equivalent Te(2)Ni8 hexagonal bipyramids, faces with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, faces with four equivalent Ni(3)Ni8Sb4 cuboctahedra, and faces with four equivalent Sb(1)Ni12 cuboctahedra. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 5-coordinate geometry to one Ni(4) and four equivalent Ni(1) atoms. In the second Te site, Te(2) is bonded to four equivalent Ni(2) and four equivalent Ni(4) atoms to form distorted TeNi8 hexagonal bipyramids that share corners with four equivalent Ni(3)Ni8Sb4 cuboctahedra, corners with four equivalent Te(2)Ni8 hexagonal bipyramids, edges with four equivalent Sb(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra,  a faceface with one Ni(3)Ni8Sb4 cuboctahedra, faces with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, and faces with four equivalent Te(2)Ni8 hexagonal bipyramids.
Ni6SbTe2 crystallizes in the tetragonal I4mm space group. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 10-coordinate geometry to two equivalent Ni(3), four equivalent Ni(1), two equivalent Sb(1), and two equivalent Te(1) atoms. Both Ni(1)-Ni(3) bond lengths are 2.62 Å. All Ni(1)-Ni(1) bond lengths are 2.69 Å. Both Ni(1)-Sb(1) bond lengths are 2.63 Å. Both Ni(1)-Te(1) bond lengths are 2.51 Å. In the second Ni site, Ni(2) is bonded to two equivalent Ni(3), two equivalent Ni(4), four equivalent Ni(2), two equivalent Sb(1), and two equivalent Te(2) atoms to form distorted NiNi8Sb2Te2 cuboctahedra that share corners with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, edges with four equivalent Ni(3)Ni8Sb4 cuboctahedra, edges with four equivalent Sb(1)Ni12 cuboctahedra, edges with four equivalent Te(2)Ni8 hexagonal bipyramids, faces with two equivalent Ni(3)Ni8Sb4 cuboctahedra, faces with two equivalent Sb(1)Ni12 cuboctahedra, faces with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, and faces with two equivalent Te(2)Ni8 hexagonal bipyramids. Both Ni(2)-Ni(3) bond lengths are 2.62 Å. Both Ni(2)-Ni(4) bond lengths are 2.67 Å. All Ni(2)-Ni(2) bond lengths are 2.69 Å. Both Ni(2)-Sb(1) bond lengths are 2.61 Å. Both Ni(2)-Te(2) bond lengths are 2.59 Å. In the third Ni site, Ni(3) is bonded to four equivalent Ni(1), four equivalent Ni(2), and four equivalent Sb(1) atoms to form NiNi8Sb4 cuboctahedra that share corners with four equivalent Ni(3)Ni8Sb4 cuboctahedra, corners with four equivalent Te(2)Ni8 hexagonal bipyramids, edges with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, faces with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, faces with four equivalent Ni(3)Ni8Sb4 cuboctahedra, faces with four equivalent Sb(1)Ni12 cuboctahedra, and  a faceface with one Te(2)Ni8 hexagonal bipyramid. All Ni(3)-Sb(1) bond lengths are 2.69 Å. In the fourth Ni site, Ni(4) is bonded in a 9-coordinate geometry to four equivalent Ni(2), one Te(1), and four equivalent Te(2) atoms. The Ni(4)-Te(1) bond length is 2.51 Å. All Ni(4)-Te(2) bond lengths are 2.70 Å. Sb(1) is bonded to four equivalent Ni(1), four equivalent Ni(2), and four equivalent Ni(3) atoms to form SbNi12 cuboctahedra that share corners with four equivalent Sb(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, edges with four equivalent Te(2)Ni8 hexagonal bipyramids, faces with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, faces with four equivalent Ni(3)Ni8Sb4 cuboctahedra, and faces with four equivalent Sb(1)Ni12 cuboctahedra. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded in a 5-coordinate geometry to one Ni(4) and four equivalent Ni(1) atoms. In the second Te site, Te(2) is bonded to four equivalent Ni(2) and four equivalent Ni(4) atoms to form distorted TeNi8 hexagonal bipyramids that share corners with four equivalent Ni(3)Ni8Sb4 cuboctahedra, corners with four equivalent Te(2)Ni8 hexagonal bipyramids, edges with four equivalent Sb(1)Ni12 cuboctahedra, edges with eight equivalent Ni(2)Ni8Sb2Te2 cuboctahedra,  a faceface with one Ni(3)Ni8Sb4 cuboctahedra, faces with four equivalent Ni(2)Ni8Sb2Te2 cuboctahedra, and faces with four equivalent Te(2)Ni8 hexagonal bipyramids.