Y2Fe15Ga2 crystallizes in the trigonal R-3m space group. Y(1) is bonded in a 19-coordinate geometry to three equivalent Fe(1), six equivalent Fe(2), nine equivalent Fe(3), and one Ga(1) atom. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Y(1), four equivalent Fe(2), four equivalent Fe(3), and two equivalent Ga(1) atoms to form distorted FeY2Ga2Fe8 cuboctahedra that share corners with four equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, corners with ten equivalent Fe(3)Y3GaFe8 cuboctahedra, edges with six equivalent Fe(3)Y3GaFe8 cuboctahedra, faces with four equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, and faces with six equivalent Fe(3)Y3GaFe8 cuboctahedra. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to two equivalent Y(1), two equivalent Fe(1), two equivalent Fe(2), four equivalent Fe(3), and two equivalent Ga(1) atoms. In the third Fe site, Fe(3) is bonded to three equivalent Y(1), two equivalent Fe(1), two equivalent Fe(3), four equivalent Fe(2), and one Ga(1) atom to form FeY3GaFe8 cuboctahedra that share corners with five equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, corners with ten equivalent Fe(3)Y3GaFe8 cuboctahedra, edges with three equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, edges with five equivalent Fe(3)Y3GaFe8 cuboctahedra, faces with three equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, and faces with seven equivalent Fe(3)Y3GaFe8 cuboctahedra. Ga(1) is bonded in a 14-coordinate geometry to one Y(1), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and one Ga(1) atom.
Y2Fe15Ga2 crystallizes in the trigonal R-3m space group. Y(1) is bonded in a 19-coordinate geometry to three equivalent Fe(1), six equivalent Fe(2), nine equivalent Fe(3), and one Ga(1) atom. All Y(1)-Fe(1) bond lengths are 3.32 Å. All Y(1)-Fe(2) bond lengths are 2.98 Å. There are a spread of Y(1)-Fe(3) bond distances ranging from 3.03-3.26 Å. The Y(1)-Ga(1) bond length is 3.05 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Y(1), four equivalent Fe(2), four equivalent Fe(3), and two equivalent Ga(1) atoms to form distorted FeY2Ga2Fe8 cuboctahedra that share corners with four equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, corners with ten equivalent Fe(3)Y3GaFe8 cuboctahedra, edges with six equivalent Fe(3)Y3GaFe8 cuboctahedra, faces with four equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, and faces with six equivalent Fe(3)Y3GaFe8 cuboctahedra. All Fe(1)-Fe(2) bond lengths are 2.45 Å. All Fe(1)-Fe(3) bond lengths are 2.45 Å. Both Fe(1)-Ga(1) bond lengths are 2.57 Å. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to two equivalent Y(1), two equivalent Fe(1), two equivalent Fe(2), four equivalent Fe(3), and two equivalent Ga(1) atoms. Both Fe(2)-Fe(2) bond lengths are 2.53 Å. There are two shorter (2.53 Å) and two longer (2.61 Å) Fe(2)-Fe(3) bond lengths. Both Fe(2)-Ga(1) bond lengths are 2.84 Å. In the third Fe site, Fe(3) is bonded to three equivalent Y(1), two equivalent Fe(1), two equivalent Fe(3), four equivalent Fe(2), and one Ga(1) atom to form FeY3GaFe8 cuboctahedra that share corners with five equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, corners with ten equivalent Fe(3)Y3GaFe8 cuboctahedra, edges with three equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, edges with five equivalent Fe(3)Y3GaFe8 cuboctahedra, faces with three equivalent Fe(1)Y2Ga2Fe8 cuboctahedra, and faces with seven equivalent Fe(3)Y3GaFe8 cuboctahedra. Both Fe(3)-Fe(3) bond lengths are 2.44 Å. The Fe(3)-Ga(1) bond length is 2.61 Å. Ga(1) is bonded in a 14-coordinate geometry to one Y(1), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(2), and one Ga(1) atom. The Ga(1)-Ga(1) bond length is 2.57 Å.