Ta3Fe8Al is Hexagonal Laves-derived structured and crystallizes in the trigonal P3m1 space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 16-coordinate geometry to one Ta(2), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(4), and three equivalent Al(1) atoms. In the second Ta site, Ta(2) is bonded in a 16-coordinate geometry to one Ta(1), three equivalent Ta(3), three equivalent Fe(2), three equivalent Fe(3), and six equivalent Fe(4) atoms. In the third Ta site, Ta(3) is bonded in a 16-coordinate geometry to three equivalent Ta(2), three equivalent Fe(2), three equivalent Fe(4), six equivalent Fe(3), and one Al(1) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent Ta(1), three equivalent Fe(3), three equivalent Fe(4), and three equivalent Al(1) atoms to form FeTa3Al3Fe6 cuboctahedra that share corners with six equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, corners with six equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with six equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with two equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with nine equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, and faces with nine equivalent Fe(4)Ta5AlFe6 cuboctahedra. In the second Fe site, Fe(2) is bonded to three equivalent Ta(2), three equivalent Ta(3), three equivalent Fe(3), and three equivalent Fe(4) atoms to form FeTa6Fe6 cuboctahedra that share corners with six equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, corners with six equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with six equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with two equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with nine equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, and faces with nine equivalent Fe(4)Ta5AlFe6 cuboctahedra. In the third Fe site, Fe(3) is bonded to one Ta(1), one Ta(2), two equivalent Ta(3), one Fe(1), one Fe(2), four equivalent Fe(3), and two equivalent Al(1) atoms to form FeTa4Al2Fe6 cuboctahedra that share corners with two equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, corners with two equivalent Fe(2)Ta6Fe6 cuboctahedra, corners with four equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, corners with ten equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with two equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, edges with four equivalent Fe(4)Ta5AlFe6 cuboctahedra, faces with three equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with three equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with four equivalent Fe(4)Ta5AlFe6 cuboctahedra, and faces with eight equivalent Fe(3)Ta4Al2Fe6 cuboctahedra. In the fourth Fe site, Fe(4) is bonded to one Ta(3), two equivalent Ta(1), two equivalent Ta(2), one Fe(1), one Fe(2), four equivalent Fe(4), and one Al(1) atom to form FeTa5AlFe6 cuboctahedra that share corners with two equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, corners with two equivalent Fe(2)Ta6Fe6 cuboctahedra, corners with four equivalent Fe(4)Ta5AlFe6 cuboctahedra, corners with ten equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, edges with two equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with four equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, faces with three equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with three equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with four equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, and faces with eight equivalent Fe(4)Ta5AlFe6 cuboctahedra. Al(1) is bonded in a 16-coordinate geometry to one Ta(3), three equivalent Ta(1), three equivalent Fe(1), three equivalent Fe(4), and six equivalent Fe(3) atoms.
Ta3Fe8Al is Hexagonal Laves-derived structured and crystallizes in the trigonal P3m1 space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded in a 16-coordinate geometry to one Ta(2), three equivalent Fe(1), three equivalent Fe(3), six equivalent Fe(4), and three equivalent Al(1) atoms. The Ta(1)-Ta(2) bond length is 2.91 Å. All Ta(1)-Fe(1) bond lengths are 2.78 Å. All Ta(1)-Fe(3) bond lengths are 2.77 Å. All Ta(1)-Fe(4) bond lengths are 2.79 Å. All Ta(1)-Al(1) bond lengths are 2.90 Å. In the second Ta site, Ta(2) is bonded in a 16-coordinate geometry to one Ta(1), three equivalent Ta(3), three equivalent Fe(2), three equivalent Fe(3), and six equivalent Fe(4) atoms. All Ta(2)-Ta(3) bond lengths are 2.95 Å. All Ta(2)-Fe(2) bond lengths are 2.77 Å. All Ta(2)-Fe(3) bond lengths are 2.83 Å. All Ta(2)-Fe(4) bond lengths are 2.77 Å. In the third Ta site, Ta(3) is bonded in a 16-coordinate geometry to three equivalent Ta(2), three equivalent Fe(2), three equivalent Fe(4), six equivalent Fe(3), and one Al(1) atom. All Ta(3)-Fe(2) bond lengths are 2.80 Å. All Ta(3)-Fe(4) bond lengths are 2.87 Å. All Ta(3)-Fe(3) bond lengths are 2.74 Å. The Ta(3)-Al(1) bond length is 2.86 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to three equivalent Ta(1), three equivalent Fe(3), three equivalent Fe(4), and three equivalent Al(1) atoms to form FeTa3Al3Fe6 cuboctahedra that share corners with six equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, corners with six equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with six equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with two equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with nine equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, and faces with nine equivalent Fe(4)Ta5AlFe6 cuboctahedra. All Fe(1)-Fe(3) bond lengths are 2.38 Å. All Fe(1)-Fe(4) bond lengths are 2.41 Å. All Fe(1)-Al(1) bond lengths are 2.77 Å. In the second Fe site, Fe(2) is bonded to three equivalent Ta(2), three equivalent Ta(3), three equivalent Fe(3), and three equivalent Fe(4) atoms to form FeTa6Fe6 cuboctahedra that share corners with six equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, corners with six equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with six equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with two equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with nine equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, and faces with nine equivalent Fe(4)Ta5AlFe6 cuboctahedra. All Fe(2)-Fe(3) bond lengths are 2.45 Å. All Fe(2)-Fe(4) bond lengths are 2.38 Å. In the third Fe site, Fe(3) is bonded to one Ta(1), one Ta(2), two equivalent Ta(3), one Fe(1), one Fe(2), four equivalent Fe(3), and two equivalent Al(1) atoms to form FeTa4Al2Fe6 cuboctahedra that share corners with two equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, corners with two equivalent Fe(2)Ta6Fe6 cuboctahedra, corners with four equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, corners with ten equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with two equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, edges with four equivalent Fe(4)Ta5AlFe6 cuboctahedra, faces with three equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with three equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with four equivalent Fe(4)Ta5AlFe6 cuboctahedra, and faces with eight equivalent Fe(3)Ta4Al2Fe6 cuboctahedra. There are two shorter (2.32 Å) and two longer (2.41 Å) Fe(3)-Fe(3) bond lengths. Both Fe(3)-Al(1) bond lengths are 2.78 Å. In the fourth Fe site, Fe(4) is bonded to one Ta(3), two equivalent Ta(1), two equivalent Ta(2), one Fe(1), one Fe(2), four equivalent Fe(4), and one Al(1) atom to form FeTa5AlFe6 cuboctahedra that share corners with two equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, corners with two equivalent Fe(2)Ta6Fe6 cuboctahedra, corners with four equivalent Fe(4)Ta5AlFe6 cuboctahedra, corners with ten equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, edges with two equivalent Fe(4)Ta5AlFe6 cuboctahedra, edges with four equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, faces with three equivalent Fe(1)Ta3Al3Fe6 cuboctahedra, faces with three equivalent Fe(2)Ta6Fe6 cuboctahedra, faces with four equivalent Fe(3)Ta4Al2Fe6 cuboctahedra, and faces with eight equivalent Fe(4)Ta5AlFe6 cuboctahedra. There are two shorter (2.31 Å) and two longer (2.42 Å) Fe(4)-Fe(4) bond lengths. The Fe(4)-Al(1) bond length is 2.78 Å. Al(1) is bonded in a 16-coordinate geometry to one Ta(3), three equivalent Ta(1), three equivalent Fe(1), three equivalent Fe(4), and six equivalent Fe(3) atoms.