Nd8CoGa3 crystallizes in the hexagonal P6_3mc space group. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to one Co(1) and four equivalent Ga(1) atoms to form distorted NdGa4Co trigonal pyramids that share corners with two equivalent Nd(4)Ga6 octahedra, corners with three equivalent Nd(2)Ga3Co tetrahedra, corners with six equivalent Nd(1)Ga4Co trigonal pyramids,  an edgeedge with one Nd(2)Ga3Co tetrahedra, edges with four equivalent Nd(1)Ga4Co trigonal pyramids, and faces with two equivalent Nd(4)Ga6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. In the second Nd site, Nd(2) is bonded to one Co(1) and three equivalent Ga(1) atoms to form distorted NdGa3Co tetrahedra that share corners with six equivalent Nd(4)Ga6 octahedra, corners with nine equivalent Nd(1)Ga4Co trigonal pyramids, and edges with three equivalent Nd(1)Ga4Co trigonal pyramids. The corner-sharing octahedral tilt angles range from 14-47°. In the third Nd site, Nd(3) is bonded in a 3-coordinate geometry to one Co(1) and four equivalent Ga(1) atoms. In the fourth Nd site, Nd(4) is bonded to six equivalent Ga(1) atoms to form distorted NdGa6 octahedra that share corners with six equivalent Nd(2)Ga3Co tetrahedra, corners with six equivalent Nd(1)Ga4Co trigonal pyramids, faces with two equivalent Nd(4)Ga6 octahedra, and faces with six equivalent Nd(1)Ga4Co trigonal pyramids. Co(1) is bonded in a 7-coordinate geometry to one Nd(2), three equivalent Nd(1), and three equivalent Nd(3) atoms. Ga(1) is bonded in a 11-coordinate geometry to one Nd(2), two equivalent Nd(4), four equivalent Nd(1), and four equivalent Nd(3) atoms.
Nd8CoGa3 crystallizes in the hexagonal P6_3mc space group. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to one Co(1) and four equivalent Ga(1) atoms to form distorted NdGa4Co trigonal pyramids that share corners with two equivalent Nd(4)Ga6 octahedra, corners with three equivalent Nd(2)Ga3Co tetrahedra, corners with six equivalent Nd(1)Ga4Co trigonal pyramids,  an edgeedge with one Nd(2)Ga3Co tetrahedra, edges with four equivalent Nd(1)Ga4Co trigonal pyramids, and faces with two equivalent Nd(4)Ga6 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. The Nd(1)-Co(1) bond length is 2.96 Å. There are a spread of Nd(1)-Ga(1) bond distances ranging from 3.05-3.79 Å. In the second Nd site, Nd(2) is bonded to one Co(1) and three equivalent Ga(1) atoms to form distorted NdGa3Co tetrahedra that share corners with six equivalent Nd(4)Ga6 octahedra, corners with nine equivalent Nd(1)Ga4Co trigonal pyramids, and edges with three equivalent Nd(1)Ga4Co trigonal pyramids. The corner-sharing octahedral tilt angles range from 14-47°. The Nd(2)-Co(1) bond length is 2.69 Å. All Nd(2)-Ga(1) bond lengths are 3.21 Å. In the third Nd site, Nd(3) is bonded in a 3-coordinate geometry to one Co(1) and four equivalent Ga(1) atoms. The Nd(3)-Co(1) bond length is 2.87 Å. There are two shorter (3.26 Å) and two longer (3.85 Å) Nd(3)-Ga(1) bond lengths. In the fourth Nd site, Nd(4) is bonded to six equivalent Ga(1) atoms to form distorted NdGa6 octahedra that share corners with six equivalent Nd(2)Ga3Co tetrahedra, corners with six equivalent Nd(1)Ga4Co trigonal pyramids, faces with two equivalent Nd(4)Ga6 octahedra, and faces with six equivalent Nd(1)Ga4Co trigonal pyramids. There are three shorter (3.43 Å) and three longer (3.48 Å) Nd(4)-Ga(1) bond lengths. Co(1) is bonded in a 7-coordinate geometry to one Nd(2), three equivalent Nd(1), and three equivalent Nd(3) atoms. Ga(1) is bonded in a 11-coordinate geometry to one Nd(2), two equivalent Nd(4), four equivalent Nd(1), and four equivalent Nd(3) atoms.