TbCo3Ga2 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Co(2), and six equivalent Ga(1) atoms. In the second Tb site, Tb(2) is bonded in a hexagonal planar geometry to six equivalent Co(1) and twelve equivalent Ga(1) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Tb(2), two equivalent Tb(1), two equivalent Co(2), and four equivalent Ga(1) atoms. In the second Co site, Co(2) is bonded to four equivalent Tb(1), four equivalent Co(1), and four equivalent Ga(1) atoms to form a mixture of face and corner-sharing CoTb4Ga4Co4 cuboctahedra. Ga(1) is bonded in a 12-coordinate geometry to two equivalent Tb(1), two equivalent Tb(2), two equivalent Co(2), four equivalent Co(1), and two equivalent Ga(1) atoms.
TbCo3Ga2 crystallizes in the hexagonal P6/mmm space group. There are two inequivalent Tb sites. In the first Tb site, Tb(1) is bonded in a 18-coordinate geometry to six equivalent Co(1), six equivalent Co(2), and six equivalent Ga(1) atoms. All Tb(1)-Co(1) bond lengths are 3.02 Å. All Tb(1)-Co(2) bond lengths are 3.22 Å. All Tb(1)-Ga(1) bond lengths are 3.08 Å. In the second Tb site, Tb(2) is bonded in a hexagonal planar geometry to six equivalent Co(1) and twelve equivalent Ga(1) atoms. All Tb(2)-Co(1) bond lengths are 2.85 Å. All Tb(2)-Ga(1) bond lengths are 3.42 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Tb(2), two equivalent Tb(1), two equivalent Co(2), and four equivalent Ga(1) atoms. Both Co(1)-Co(2) bond lengths are 2.48 Å. All Co(1)-Ga(1) bond lengths are 2.42 Å. In the second Co site, Co(2) is bonded to four equivalent Tb(1), four equivalent Co(1), and four equivalent Ga(1) atoms to form a mixture of face and corner-sharing CoTb4Ga4Co4 cuboctahedra. All Co(2)-Ga(1) bond lengths are 2.53 Å. Ga(1) is bonded in a 12-coordinate geometry to two equivalent Tb(1), two equivalent Tb(2), two equivalent Co(2), four equivalent Co(1), and two equivalent Ga(1) atoms. Both Ga(1)-Ga(1) bond lengths are 2.84 Å.