NiAlNb crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 16-coordinate geometry to one Nb(1), three equivalent Nb(2), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), three equivalent Al(1), and four equivalent Al(2) atoms. In the second Nb site, Nb(2) is bonded in a 16-coordinate geometry to one Nb(2), three equivalent Nb(1), one Ni(1), two equivalent Ni(3), four equivalent Ni(2), two equivalent Al(2), and three equivalent Al(1) atoms. In the third Nb site, Nb(1) is bonded in a 16-coordinate geometry to one Nb(1), three equivalent Nb(2), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), three equivalent Al(1), and four equivalent Al(2) atoms. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Nb(2); four Nb(1,1); two equivalent Al(1); and four equivalent Al(2) atoms to form distorted NiNb6Al6 cuboctahedra that share corners with two equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, corners with four equivalent Ni(1)Nb6Al6 cuboctahedra, corners with eight equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, edges with two equivalent Ni(1)Nb6Al6 cuboctahedra, edges with four equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, and faces with four equivalent Ni(2)Nb6Al2Ni4 cuboctahedra. In the second Ni site, Ni(2) is bonded to two equivalent Nb(1), four equivalent Nb(2), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Al(1) atoms to form distorted NiNb6Al2Ni4 cuboctahedra that share corners with four equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, corners with four equivalent Ni(1)Nb6Al6 cuboctahedra, edges with two equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, faces with two equivalent Ni(1)Nb6Al6 cuboctahedra, faces with four equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, and faces with four equivalent Ni(3)Nb6Al2Ni4 cuboctahedra. In the third Ni site, Ni(3) is bonded to two equivalent Nb(1), four equivalent Nb(2), four equivalent Ni(2), and two equivalent Al(1) atoms to form distorted NiNb6Al2Ni4 cuboctahedra that share corners with two equivalent Ni(1)Nb6Al6 cuboctahedra, corners with four equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, edges with two equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, edges with four equivalent Ni(1)Nb6Al6 cuboctahedra, and faces with eight equivalent Ni(2)Nb6Al2Ni4 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 4-coordinate geometry to three equivalent Nb(1), three equivalent Nb(2), one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Nb(2); four Nb(1,1); two equivalent Ni(1); two equivalent Al(1); and two equivalent Al(2) atoms.
NiAlNb crystallizes in the orthorhombic Amm2 space group. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 16-coordinate geometry to one Nb(1), three equivalent Nb(2), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), three equivalent Al(1), and four equivalent Al(2) atoms. The Nb(1)-Nb(1) bond length is 3.18 Å. There is one shorter (2.96 Å) and two longer (3.06 Å) Nb(1)-Nb(2) bond lengths. The Nb(1)-Ni(3) bond length is 2.78 Å. Both Nb(1)-Ni(1) bond lengths are 2.97 Å. Both Nb(1)-Ni(2) bond lengths are 2.78 Å. There are two shorter (2.90 Å) and one longer (2.94 Å) Nb(1)-Al(1) bond length. There are two shorter (2.90 Å) and two longer (2.97 Å) Nb(1)-Al(2) bond lengths. In the second Nb site, Nb(2) is bonded in a 16-coordinate geometry to one Nb(2), three equivalent Nb(1), one Ni(1), two equivalent Ni(3), four equivalent Ni(2), two equivalent Al(2), and three equivalent Al(1) atoms. The Nb(2)-Nb(2) bond length is 2.86 Å. The Nb(2)-Ni(1) bond length is 2.97 Å. Both Nb(2)-Ni(3) bond lengths are 2.89 Å. There are two shorter (2.82 Å) and two longer (2.88 Å) Nb(2)-Ni(2) bond lengths. Both Nb(2)-Al(2) bond lengths are 2.90 Å. There is one shorter (2.84 Å) and two longer (2.94 Å) Nb(2)-Al(1) bond lengths. In the third Nb site, Nb(1) is bonded in a 16-coordinate geometry to one Nb(1), three equivalent Nb(2), one Ni(3), two equivalent Ni(1), two equivalent Ni(2), three equivalent Al(1), and four equivalent Al(2) atoms. The Nb(1)-Nb(1) bond length is 3.18 Å. There is one shorter (2.96 Å) and two longer (3.06 Å) Nb(1)-Nb(2) bond lengths. The Nb(1)-Ni(3) bond length is 2.78 Å. Both Nb(1)-Ni(1) bond lengths are 2.97 Å. Both Nb(1)-Ni(2) bond lengths are 2.78 Å. There are two shorter (2.90 Å) and one longer (2.94 Å) Nb(1)-Al(1) bond length. There are two shorter (2.90 Å) and two longer (2.97 Å) Nb(1)-Al(2) bond lengths. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent Nb(2); four Nb(1,1); two equivalent Al(1); and four equivalent Al(2) atoms to form distorted NiNb6Al6 cuboctahedra that share corners with two equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, corners with four equivalent Ni(1)Nb6Al6 cuboctahedra, corners with eight equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, edges with two equivalent Ni(1)Nb6Al6 cuboctahedra, edges with four equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, and faces with four equivalent Ni(2)Nb6Al2Ni4 cuboctahedra. Both Ni(1)-Al(1) bond lengths are 2.47 Å. There are two shorter (2.42 Å) and two longer (2.51 Å) Ni(1)-Al(2) bond lengths. In the second Ni site, Ni(2) is bonded to two equivalent Nb(1), four equivalent Nb(2), two equivalent Ni(2), two equivalent Ni(3), and two equivalent Al(1) atoms to form distorted NiNb6Al2Ni4 cuboctahedra that share corners with four equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, corners with four equivalent Ni(1)Nb6Al6 cuboctahedra, edges with two equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, faces with two equivalent Ni(1)Nb6Al6 cuboctahedra, faces with four equivalent Ni(2)Nb6Al2Ni4 cuboctahedra, and faces with four equivalent Ni(3)Nb6Al2Ni4 cuboctahedra. There is one shorter (2.41 Å) and one longer (2.62 Å) Ni(2)-Ni(2) bond length. There is one shorter (2.39 Å) and one longer (2.55 Å) Ni(2)-Ni(3) bond length. Both Ni(2)-Al(1) bond lengths are 2.40 Å. In the third Ni site, Ni(3) is bonded to two equivalent Nb(1), four equivalent Nb(2), four equivalent Ni(2), and two equivalent Al(1) atoms to form distorted NiNb6Al2Ni4 cuboctahedra that share corners with two equivalent Ni(1)Nb6Al6 cuboctahedra, corners with four equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, edges with two equivalent Ni(3)Nb6Al2Ni4 cuboctahedra, edges with four equivalent Ni(1)Nb6Al6 cuboctahedra, and faces with eight equivalent Ni(2)Nb6Al2Ni4 cuboctahedra. Both Ni(3)-Al(1) bond lengths are 2.43 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded in a 4-coordinate geometry to three equivalent Nb(1), three equivalent Nb(2), one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent Al(2) atoms. Both Al(1)-Al(2) bond lengths are 2.61 Å. In the second Al site, Al(2) is bonded in a 12-coordinate geometry to two equivalent Nb(2); four Nb(1,1); two equivalent Ni(1); two equivalent Al(1); and two equivalent Al(2) atoms. There is one shorter (2.43 Å) and one longer (2.59 Å) Al(2)-Al(2) bond length.