Co2NiAl9 crystallizes in the orthorhombic Immm space group. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Al(6), two equivalent Al(1), two equivalent Al(8), and four equivalent Al(7) atoms. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Al(8), two equivalent Al(10), two equivalent Al(4), and four equivalent Al(2) atoms. In the third Co site, Co(3) is bonded in a 10-coordinate geometry to one Al(1), one Al(9), two equivalent Al(10), two equivalent Al(4), two equivalent Al(5), and two equivalent Al(7) atoms. Ni(1) is bonded in a 9-coordinate geometry to one Al(3), one Al(4), one Al(5), two equivalent Al(7), and four equivalent Al(2) atoms. There are ten inequivalent Al sites. In the first Al site, Al(1) is bonded in a 4-coordinate geometry to two equivalent Co(1) and two equivalent Co(3) atoms. In the second Al site, Al(10) is bonded in a 3-coordinate geometry to one Co(2), two equivalent Co(3), one Al(9), and two equivalent Al(4) atoms. In the third Al site, Al(2) is bonded in a 3-coordinate geometry to one Co(2), two equivalent Ni(1), and one Al(4) atom. In the fourth Al site, Al(3) is bonded in a bent 150 degrees geometry to two equivalent Ni(1) atoms. In the fifth Al site, Al(4) is bonded in a 11-coordinate geometry to one Co(2), two equivalent Co(3), one Ni(1), one Al(4), two equivalent Al(10), two equivalent Al(2), and two equivalent Al(7) atoms. In the sixth Al site, Al(5) is bonded in a 3-coordinate geometry to two equivalent Co(3), one Ni(1), and one Al(9) atom. In the seventh Al site, Al(6) is bonded in a linear geometry to two equivalent Co(1) atoms. In the eighth Al site, Al(7) is bonded in a 3-coordinate geometry to one Co(1), one Co(3), one Ni(1), and one Al(4) atom. In the ninth Al site, Al(8) is bonded in a 3-coordinate geometry to one Co(2) and two equivalent Co(1) atoms. In the tenth Al site, Al(9) is bonded in a 12-coordinate geometry to four equivalent Co(3), four equivalent Al(10), and four equivalent Al(5) atoms.
Co2NiAl9 crystallizes in the orthorhombic Immm space group. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded in a 9-coordinate geometry to one Al(6), two equivalent Al(1), two equivalent Al(8), and four equivalent Al(7) atoms. The Co(1)-Al(6) bond length is 2.37 Å. Both Co(1)-Al(1) bond lengths are 2.46 Å. Both Co(1)-Al(8) bond lengths are 2.52 Å. All Co(1)-Al(7) bond lengths are 2.47 Å. In the second Co site, Co(2) is bonded in a 9-coordinate geometry to one Al(8), two equivalent Al(10), two equivalent Al(4), and four equivalent Al(2) atoms. The Co(2)-Al(8) bond length is 2.55 Å. Both Co(2)-Al(10) bond lengths are 2.35 Å. Both Co(2)-Al(4) bond lengths are 2.61 Å. All Co(2)-Al(2) bond lengths are 2.37 Å. In the third Co site, Co(3) is bonded in a 10-coordinate geometry to one Al(1), one Al(9), two equivalent Al(10), two equivalent Al(4), two equivalent Al(5), and two equivalent Al(7) atoms. The Co(3)-Al(1) bond length is 2.50 Å. The Co(3)-Al(9) bond length is 2.55 Å. Both Co(3)-Al(10) bond lengths are 2.57 Å. Both Co(3)-Al(4) bond lengths are 2.59 Å. Both Co(3)-Al(5) bond lengths are 2.52 Å. Both Co(3)-Al(7) bond lengths are 2.63 Å. Ni(1) is bonded in a 9-coordinate geometry to one Al(3), one Al(4), one Al(5), two equivalent Al(7), and four equivalent Al(2) atoms. The Ni(1)-Al(3) bond length is 2.32 Å. The Ni(1)-Al(4) bond length is 2.63 Å. The Ni(1)-Al(5) bond length is 2.48 Å. Both Ni(1)-Al(7) bond lengths are 2.45 Å. All Ni(1)-Al(2) bond lengths are 2.50 Å. There are ten inequivalent Al sites. In the first Al site, Al(1) is bonded in a 4-coordinate geometry to two equivalent Co(1) and two equivalent Co(3) atoms. In the second Al site, Al(10) is bonded in a 3-coordinate geometry to one Co(2), two equivalent Co(3), one Al(9), and two equivalent Al(4) atoms. The Al(10)-Al(9) bond length is 2.50 Å. Both Al(10)-Al(4) bond lengths are 2.64 Å. In the third Al site, Al(2) is bonded in a 3-coordinate geometry to one Co(2), two equivalent Ni(1), and one Al(4) atom. The Al(2)-Al(4) bond length is 2.83 Å. In the fourth Al site, Al(3) is bonded in a bent 150 degrees geometry to two equivalent Ni(1) atoms. In the fifth Al site, Al(4) is bonded in a 11-coordinate geometry to one Co(2), two equivalent Co(3), one Ni(1), one Al(4), two equivalent Al(10), two equivalent Al(2), and two equivalent Al(7) atoms. The Al(4)-Al(4) bond length is 2.67 Å. Both Al(4)-Al(7) bond lengths are 2.67 Å. In the sixth Al site, Al(5) is bonded in a 3-coordinate geometry to two equivalent Co(3), one Ni(1), and one Al(9) atom. The Al(5)-Al(9) bond length is 2.88 Å. In the seventh Al site, Al(6) is bonded in a linear geometry to two equivalent Co(1) atoms. In the eighth Al site, Al(7) is bonded in a 3-coordinate geometry to one Co(1), one Co(3), one Ni(1), and one Al(4) atom. In the ninth Al site, Al(8) is bonded in a 3-coordinate geometry to one Co(2) and two equivalent Co(1) atoms. In the tenth Al site, Al(9) is bonded in a 12-coordinate geometry to four equivalent Co(3), four equivalent Al(10), and four equivalent Al(5) atoms.