Tm2Fe14Ga3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 18-coordinate geometry to six equivalent Fe(2) and twelve equivalent Fe(3) atoms. In the second Tm site, Tm(2) is bonded in a 20-coordinate geometry to two equivalent Fe(1), six equivalent Fe(2), six equivalent Fe(3), and six equivalent Ga(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Tm(2), one Fe(1), three equivalent Fe(3), six equivalent Fe(2), and three equivalent Ga(1) atoms. In the second Fe site, Fe(2) is bonded in a 9-coordinate geometry to one Tm(1), one Tm(2), one Fe(2), two equivalent Fe(1), four equivalent Fe(3), and two equivalent Ga(1) atoms. In the third Fe site, Fe(3) is bonded to one Tm(2), two equivalent Tm(1), one Fe(1), two equivalent Fe(3), four equivalent Fe(2), and two equivalent Ga(1) atoms to form distorted FeTm3Ga2Fe7 cuboctahedra that share corners with five equivalent Ga(1)Tm2Fe10 cuboctahedra, corners with ten equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, edges with three equivalent Ga(1)Tm2Fe10 cuboctahedra, edges with five equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, faces with two equivalent Ga(1)Tm2Fe10 cuboctahedra, and faces with eight equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra. Ga(1) is bonded to two equivalent Tm(2), two equivalent Fe(1), four equivalent Fe(2), and four equivalent Fe(3) atoms to form GaTm2Fe10 cuboctahedra that share corners with four equivalent Ga(1)Tm2Fe10 cuboctahedra, corners with ten equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, edges with six equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, faces with four equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, and faces with six equivalent Ga(1)Tm2Fe10 cuboctahedra.
Tm2Fe14Ga3 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Tm sites. In the first Tm site, Tm(1) is bonded in a 18-coordinate geometry to six equivalent Fe(2) and twelve equivalent Fe(3) atoms. All Tm(1)-Fe(2) bond lengths are 2.85 Å. There are six shorter (3.12 Å) and six longer (3.26 Å) Tm(1)-Fe(3) bond lengths. In the second Tm site, Tm(2) is bonded in a 20-coordinate geometry to two equivalent Fe(1), six equivalent Fe(2), six equivalent Fe(3), and six equivalent Ga(1) atoms. Both Tm(2)-Fe(1) bond lengths are 2.98 Å. All Tm(2)-Fe(2) bond lengths are 3.00 Å. All Tm(2)-Fe(3) bond lengths are 3.16 Å. All Tm(2)-Ga(1) bond lengths are 3.21 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Tm(2), one Fe(1), three equivalent Fe(3), six equivalent Fe(2), and three equivalent Ga(1) atoms. The Fe(1)-Fe(1) bond length is 2.29 Å. All Fe(1)-Fe(3) bond lengths are 2.69 Å. All Fe(1)-Fe(2) bond lengths are 2.90 Å. All Fe(1)-Ga(1) bond lengths are 2.62 Å. In the second Fe site, Fe(2) is bonded in a 9-coordinate geometry to one Tm(1), one Tm(2), one Fe(2), two equivalent Fe(1), four equivalent Fe(3), and two equivalent Ga(1) atoms. The Fe(2)-Fe(2) bond length is 2.51 Å. There are two shorter (2.51 Å) and two longer (2.52 Å) Fe(2)-Fe(3) bond lengths. Both Fe(2)-Ga(1) bond lengths are 2.51 Å. In the third Fe site, Fe(3) is bonded to one Tm(2), two equivalent Tm(1), one Fe(1), two equivalent Fe(3), four equivalent Fe(2), and two equivalent Ga(1) atoms to form distorted FeTm3Ga2Fe7 cuboctahedra that share corners with five equivalent Ga(1)Tm2Fe10 cuboctahedra, corners with ten equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, edges with three equivalent Ga(1)Tm2Fe10 cuboctahedra, edges with five equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, faces with two equivalent Ga(1)Tm2Fe10 cuboctahedra, and faces with eight equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra. Both Fe(3)-Fe(3) bond lengths are 2.44 Å. Both Fe(3)-Ga(1) bond lengths are 2.47 Å. Ga(1) is bonded to two equivalent Tm(2), two equivalent Fe(1), four equivalent Fe(2), and four equivalent Fe(3) atoms to form GaTm2Fe10 cuboctahedra that share corners with four equivalent Ga(1)Tm2Fe10 cuboctahedra, corners with ten equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, edges with six equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, faces with four equivalent Fe(3)Tm3Ga2Fe7 cuboctahedra, and faces with six equivalent Ga(1)Tm2Fe10 cuboctahedra.