TaNi6Al is beta Cu3Ti-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Ta(1) is bonded to six equivalent Ni(1) and six Ni(2,2,2) atoms to form TaNi12 cuboctahedra that share corners with six equivalent Ta(1)Ni12 cuboctahedra; corners with twelve Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; edges with twelve equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; and faces with six equivalent Al(1)Ni12 cuboctahedra. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with twelve equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Ta(1)Ni12 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; edges with eight Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with four equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; and faces with ten Ni(2,2,2)Ta2Al2Ni8 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with four equivalent Ta(1)Ni12 cuboctahedra; corners with fourteen Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with two equivalent Ta(1)Ni12 cuboctahedra; edges with four Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; and faces with ten equivalent Ni(1)Ta2Al2Ni8 cuboctahedra. In the third Ni site, Ni(2) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with four equivalent Ta(1)Ni12 cuboctahedra; corners with fourteen Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with two equivalent Ta(1)Ni12 cuboctahedra; edges with four Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; and faces with ten equivalent Ni(1)Ta2Al2Ni8 cuboctahedra. In the fourth Ni site, Ni(2) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with four equivalent Ta(1)Ni12 cuboctahedra; corners with fourteen Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; edges with two equivalent Ta(1)Ni12 cuboctahedra; edges with four Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with six Ni(2,2)Ta2Al2Ni8 cuboctahedra; and faces with ten equivalent Ni(1)Ta2Al2Ni8 cuboctahedra. Al(1) is bonded to six equivalent Ni(1) and six Ni(2,2,2) atoms to form AlNi12 cuboctahedra that share corners with twelve equivalent Al(1)Ni12 cuboctahedra; edges with twelve equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; edges with twelve Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; faces with six equivalent Ta(1)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; and faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra.
TaNi6Al is beta Cu3Ti-derived structured and crystallizes in the hexagonal P6_3/mmc space group. Ta(1) is bonded to six equivalent Ni(1) and six Ni(2,2,2) atoms to form TaNi12 cuboctahedra that share corners with six equivalent Ta(1)Ni12 cuboctahedra; corners with twelve Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; edges with twelve equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; and faces with six equivalent Al(1)Ni12 cuboctahedra. All Ta(1)-Ni(1) bond lengths are 2.56 Å. All Ta(1)-Ni(2,2,2) bond lengths are 2.54 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with twelve equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Ta(1)Ni12 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; edges with eight Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with four equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; and faces with ten Ni(2,2,2)Ta2Al2Ni8 cuboctahedra. There are two shorter (2.43 Å) and two longer (2.64 Å) Ni(1)-Ni(1) bond lengths. All Ni(1)-Ni(2,2,2) bond lengths are 2.51 Å. Both Ni(1)-Al(1) bond lengths are 2.54 Å. In the second Ni site, Ni(2) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with four equivalent Ta(1)Ni12 cuboctahedra; corners with fourteen Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with two equivalent Ta(1)Ni12 cuboctahedra; edges with four Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; and faces with ten equivalent Ni(1)Ta2Al2Ni8 cuboctahedra. All Ni(2)-Ni(2,2) bond lengths are 2.54 Å. Both Ni(2)-Al(1) bond lengths are 2.52 Å. In the third Ni site, Ni(2) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with four equivalent Ta(1)Ni12 cuboctahedra; corners with fourteen Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with two equivalent Ta(1)Ni12 cuboctahedra; edges with four Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; and faces with ten equivalent Ni(1)Ta2Al2Ni8 cuboctahedra. Both Ni(2)-Ni(2) bond lengths are 2.54 Å. Both Ni(2)-Al(1) bond lengths are 2.52 Å. In the fourth Ni site, Ni(2) is bonded to two equivalent Ta(1); four equivalent Ni(1); four Ni(2,2); and two equivalent Al(1) atoms to form distorted NiTa2Al2Ni8 cuboctahedra that share corners with four equivalent Ta(1)Ni12 cuboctahedra; corners with fourteen Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; edges with two equivalent Ta(1)Ni12 cuboctahedra; edges with four Ni(2,2)Ta2Al2Ni8 cuboctahedra; edges with four equivalent Al(1)Ni12 cuboctahedra; edges with eight equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; faces with two equivalent Ta(1)Ni12 cuboctahedra; faces with two equivalent Al(1)Ni12 cuboctahedra; faces with six Ni(2,2)Ta2Al2Ni8 cuboctahedra; and faces with ten equivalent Ni(1)Ta2Al2Ni8 cuboctahedra. Both Ni(2)-Al(1) bond lengths are 2.52 Å. Al(1) is bonded to six equivalent Ni(1) and six Ni(2,2,2) atoms to form AlNi12 cuboctahedra that share corners with twelve equivalent Al(1)Ni12 cuboctahedra; edges with twelve equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; edges with twelve Ni(2,2,2)Ta2Al2Ni8 cuboctahedra; faces with six equivalent Ta(1)Ni12 cuboctahedra; faces with six equivalent Ni(1)Ta2Al2Ni8 cuboctahedra; and faces with six Ni(2,2,2)Ta2Al2Ni8 cuboctahedra.