Nb12IrAu3 crystallizes in the orthorhombic Pmmm space group. There are five inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one Nb(1), one Nb(2), two equivalent Ir(1), and two equivalent Au(1) atoms. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one Nb(1), one Nb(2), two equivalent Au(1), and two equivalent Au(2) atoms. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to two equivalent Nb(3), two equivalent Au(1), and two equivalent Au(2) atoms. In the fourth Nb site, Nb(4) is bonded in a 6-coordinate geometry to two equivalent Nb(4), two equivalent Ir(1), and two equivalent Au(1) atoms. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to two equivalent Nb(5), one Ir(1), one Au(2), and two equivalent Au(1) atoms. Ir(1) is bonded to four equivalent Nb(1), four equivalent Nb(4), and four equivalent Nb(5) atoms to form IrNb12 cuboctahedra that share edges with two equivalent Au(2)Nb12 cuboctahedra, edges with four equivalent Ir(1)Nb12 cuboctahedra, and faces with eight equivalent Au(1)Nb12 cuboctahedra. There are two inequivalent Au sites. In the first Au site, Au(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), two equivalent Nb(3), two equivalent Nb(4), and four equivalent Nb(5) atoms to form AuNb12 cuboctahedra that share edges with six equivalent Au(1)Nb12 cuboctahedra, faces with four equivalent Ir(1)Nb12 cuboctahedra, and faces with four equivalent Au(2)Nb12 cuboctahedra. In the second Au site, Au(2) is bonded to four equivalent Nb(2), four equivalent Nb(3), and four equivalent Nb(5) atoms to form AuNb12 cuboctahedra that share edges with two equivalent Ir(1)Nb12 cuboctahedra, edges with four equivalent Au(2)Nb12 cuboctahedra, and faces with eight equivalent Au(1)Nb12 cuboctahedra.
Nb12IrAu3 crystallizes in the orthorhombic Pmmm space group. There are five inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to one Nb(1), one Nb(2), two equivalent Ir(1), and two equivalent Au(1) atoms. The Nb(1)-Nb(1) bond length is 2.56 Å. The Nb(1)-Nb(2) bond length is 2.64 Å. Both Nb(1)-Ir(1) bond lengths are 2.91 Å. Both Nb(1)-Au(1) bond lengths are 2.94 Å. In the second Nb site, Nb(2) is bonded in a 6-coordinate geometry to one Nb(1), one Nb(2), two equivalent Au(1), and two equivalent Au(2) atoms. The Nb(2)-Nb(2) bond length is 2.64 Å. Both Nb(2)-Au(1) bond lengths are 2.93 Å. Both Nb(2)-Au(2) bond lengths are 2.93 Å. In the third Nb site, Nb(3) is bonded in a 6-coordinate geometry to two equivalent Nb(3), two equivalent Au(1), and two equivalent Au(2) atoms. There is one shorter (2.60 Å) and one longer (2.62 Å) Nb(3)-Nb(3) bond length. Both Nb(3)-Au(1) bond lengths are 2.94 Å. Both Nb(3)-Au(2) bond lengths are 2.93 Å. In the fourth Nb site, Nb(4) is bonded in a 6-coordinate geometry to two equivalent Nb(4), two equivalent Ir(1), and two equivalent Au(1) atoms. There is one shorter (2.56 Å) and one longer (2.66 Å) Nb(4)-Nb(4) bond length. Both Nb(4)-Ir(1) bond lengths are 2.92 Å. Both Nb(4)-Au(1) bond lengths are 2.93 Å. In the fifth Nb site, Nb(5) is bonded in a 6-coordinate geometry to two equivalent Nb(5), one Ir(1), one Au(2), and two equivalent Au(1) atoms. There is one shorter (2.58 Å) and one longer (2.66 Å) Nb(5)-Nb(5) bond length. The Nb(5)-Ir(1) bond length is 2.90 Å. The Nb(5)-Au(2) bond length is 2.95 Å. Both Nb(5)-Au(1) bond lengths are 2.93 Å. Ir(1) is bonded to four equivalent Nb(1), four equivalent Nb(4), and four equivalent Nb(5) atoms to form IrNb12 cuboctahedra that share edges with two equivalent Au(2)Nb12 cuboctahedra, edges with four equivalent Ir(1)Nb12 cuboctahedra, and faces with eight equivalent Au(1)Nb12 cuboctahedra. There are two inequivalent Au sites. In the first Au site, Au(1) is bonded to two equivalent Nb(1), two equivalent Nb(2), two equivalent Nb(3), two equivalent Nb(4), and four equivalent Nb(5) atoms to form AuNb12 cuboctahedra that share edges with six equivalent Au(1)Nb12 cuboctahedra, faces with four equivalent Ir(1)Nb12 cuboctahedra, and faces with four equivalent Au(2)Nb12 cuboctahedra. In the second Au site, Au(2) is bonded to four equivalent Nb(2), four equivalent Nb(3), and four equivalent Nb(5) atoms to form AuNb12 cuboctahedra that share edges with two equivalent Ir(1)Nb12 cuboctahedra, edges with four equivalent Au(2)Nb12 cuboctahedra, and faces with eight equivalent Au(1)Nb12 cuboctahedra.