Ta3Mn8Al 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 Mn(1), three equivalent Mn(3), six equivalent Mn(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 Mn(2), three equivalent Mn(3), and six equivalent Mn(4) atoms. In the third Ta site, Ta(3) is bonded in a 16-coordinate geometry to three equivalent Ta(2), three equivalent Mn(2), three equivalent Mn(4), six equivalent Mn(3), and one Al(1) atom. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to three equivalent Ta(1), three equivalent Mn(3), three equivalent Mn(4), and three equivalent Al(1) atoms to form MnTa3Mn6Al3 cuboctahedra that share corners with six equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, corners with six equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with six equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with two equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with nine equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, and faces with nine equivalent Mn(4)Ta5Mn6Al cuboctahedra. In the second Mn site, Mn(2) is bonded to three equivalent Ta(2), three equivalent Ta(3), three equivalent Mn(3), and three equivalent Mn(4) atoms to form MnTa6Mn6 cuboctahedra that share corners with six equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, corners with six equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with six equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with two equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with nine equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, and faces with nine equivalent Mn(4)Ta5Mn6Al cuboctahedra. In the third Mn site, Mn(3) is bonded to one Ta(1), one Ta(2), two equivalent Ta(3), one Mn(1), one Mn(2), four equivalent Mn(3), and two equivalent Al(1) atoms to form MnTa4Mn6Al2 cuboctahedra that share corners with two equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, corners with two equivalent Mn(2)Ta6Mn6 cuboctahedra, corners with four equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, corners with ten equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with two equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, edges with four equivalent Mn(4)Ta5Mn6Al cuboctahedra, faces with three equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with three equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with four equivalent Mn(4)Ta5Mn6Al cuboctahedra, and faces with eight equivalent Mn(3)Ta4Mn6Al2 cuboctahedra. In the fourth Mn site, Mn(4) is bonded to one Ta(3), two equivalent Ta(1), two equivalent Ta(2), one Mn(1), one Mn(2), four equivalent Mn(4), and one Al(1) atom to form MnTa5Mn6Al cuboctahedra that share corners with two equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, corners with two equivalent Mn(2)Ta6Mn6 cuboctahedra, corners with four equivalent Mn(4)Ta5Mn6Al cuboctahedra, corners with ten equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, edges with two equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with four equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, faces with three equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with three equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with four equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, and faces with eight equivalent Mn(4)Ta5Mn6Al cuboctahedra. Al(1) is bonded in a 16-coordinate geometry to one Ta(3), three equivalent Ta(1), three equivalent Mn(1), three equivalent Mn(4), and six equivalent Mn(3) atoms.
Ta3Mn8Al 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 Mn(1), three equivalent Mn(3), six equivalent Mn(4), and three equivalent Al(1) atoms. The Ta(1)-Ta(2) bond length is 2.96 Å. All Ta(1)-Mn(1) bond lengths are 2.85 Å. All Ta(1)-Mn(3) bond lengths are 2.79 Å. All Ta(1)-Mn(4) bond lengths are 2.84 Å. All Ta(1)-Al(1) bond lengths are 2.97 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 Mn(2), three equivalent Mn(3), and six equivalent Mn(4) atoms. All Ta(2)-Ta(3) bond lengths are 2.99 Å. All Ta(2)-Mn(2) bond lengths are 2.84 Å. All Ta(2)-Mn(3) bond lengths are 2.81 Å. All Ta(2)-Mn(4) bond lengths are 2.85 Å. In the third Ta site, Ta(3) is bonded in a 16-coordinate geometry to three equivalent Ta(2), three equivalent Mn(2), three equivalent Mn(4), six equivalent Mn(3), and one Al(1) atom. All Ta(3)-Mn(2) bond lengths are 2.87 Å. All Ta(3)-Mn(4) bond lengths are 2.85 Å. All Ta(3)-Mn(3) bond lengths are 2.82 Å. The Ta(3)-Al(1) bond length is 2.88 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to three equivalent Ta(1), three equivalent Mn(3), three equivalent Mn(4), and three equivalent Al(1) atoms to form MnTa3Mn6Al3 cuboctahedra that share corners with six equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, corners with six equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with six equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with two equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with nine equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, and faces with nine equivalent Mn(4)Ta5Mn6Al cuboctahedra. All Mn(1)-Mn(3) bond lengths are 2.40 Å. All Mn(1)-Mn(4) bond lengths are 2.41 Å. All Mn(1)-Al(1) bond lengths are 2.85 Å. In the second Mn site, Mn(2) is bonded to three equivalent Ta(2), three equivalent Ta(3), three equivalent Mn(3), and three equivalent Mn(4) atoms to form MnTa6Mn6 cuboctahedra that share corners with six equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, corners with six equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with six equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with two equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with nine equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, and faces with nine equivalent Mn(4)Ta5Mn6Al cuboctahedra. All Mn(2)-Mn(3) bond lengths are 2.45 Å. All Mn(2)-Mn(4) bond lengths are 2.41 Å. In the third Mn site, Mn(3) is bonded to one Ta(1), one Ta(2), two equivalent Ta(3), one Mn(1), one Mn(2), four equivalent Mn(3), and two equivalent Al(1) atoms to form MnTa4Mn6Al2 cuboctahedra that share corners with two equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, corners with two equivalent Mn(2)Ta6Mn6 cuboctahedra, corners with four equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, corners with ten equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with two equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, edges with four equivalent Mn(4)Ta5Mn6Al cuboctahedra, faces with three equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with three equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with four equivalent Mn(4)Ta5Mn6Al cuboctahedra, and faces with eight equivalent Mn(3)Ta4Mn6Al2 cuboctahedra. There are two shorter (2.41 Å) and two longer (2.46 Å) Mn(3)-Mn(3) bond lengths. Both Mn(3)-Al(1) bond lengths are 2.84 Å. In the fourth Mn site, Mn(4) is bonded to one Ta(3), two equivalent Ta(1), two equivalent Ta(2), one Mn(1), one Mn(2), four equivalent Mn(4), and one Al(1) atom to form MnTa5Mn6Al cuboctahedra that share corners with two equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, corners with two equivalent Mn(2)Ta6Mn6 cuboctahedra, corners with four equivalent Mn(4)Ta5Mn6Al cuboctahedra, corners with ten equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, edges with two equivalent Mn(4)Ta5Mn6Al cuboctahedra, edges with four equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, faces with three equivalent Mn(1)Ta3Mn6Al3 cuboctahedra, faces with three equivalent Mn(2)Ta6Mn6 cuboctahedra, faces with four equivalent Mn(3)Ta4Mn6Al2 cuboctahedra, and faces with eight equivalent Mn(4)Ta5Mn6Al cuboctahedra. There are two shorter (2.37 Å) and two longer (2.49 Å) Mn(4)-Mn(4) bond lengths. The Mn(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 Mn(1), three equivalent Mn(4), and six equivalent Mn(3) atoms.