ZrNbAl6 is beta Cu3Ti-derived structured and crystallizes in the tetragonal P4/mmm space group. Zr(1) is bonded to four equivalent Al(2) and eight equivalent Al(3) atoms to form ZrAl12 cuboctahedra that share corners with four equivalent Zr(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Nb4Al8 cuboctahedra, edges with eight equivalent Nb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, faces with four equivalent Zr(1)Al12 cuboctahedra, and faces with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra. Nb(1) is bonded to four equivalent Al(1) and eight equivalent Al(3) atoms to form NbAl12 cuboctahedra that share corners with four equivalent Nb(1)Al12 cuboctahedra, edges with eight equivalent Zr(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Nb(1) and eight equivalent Al(3) atoms to form AlNb4Al8 cuboctahedra that share corners with four equivalent Al(1)Nb4Al8 cuboctahedra, corners with eight equivalent Zr(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with two equivalent Zr(1)Al12 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra. In the second Al site, Al(2) is bonded in a distorted square co-planar geometry to four equivalent Zr(1) and eight equivalent Al(3) atoms. In the third Al site, Al(3) is bonded to two equivalent Zr(1), two equivalent Nb(1), two equivalent Al(1), two equivalent Al(2), and four equivalent Al(3) atoms to form AlZr2Nb2Al8 cuboctahedra that share corners with twelve equivalent Al(3)Zr2Nb2Al8 cuboctahedra, edges with four equivalent Zr(1)Al12 cuboctahedra, edges with four equivalent Nb(1)Al12 cuboctahedra, edges with four equivalent Al(1)Nb4Al8 cuboctahedra, edges with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with two equivalent Zr(1)Al12 cuboctahedra, faces with two equivalent Nb(1)Al12 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, and faces with ten equivalent Al(3)Zr2Nb2Al8 cuboctahedra.
ZrNbAl6 is beta Cu3Ti-derived structured and crystallizes in the tetragonal P4/mmm space group. Zr(1) is bonded to four equivalent Al(2) and eight equivalent Al(3) atoms to form ZrAl12 cuboctahedra that share corners with four equivalent Zr(1)Al12 cuboctahedra, corners with eight equivalent Al(1)Nb4Al8 cuboctahedra, edges with eight equivalent Nb(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, faces with four equivalent Zr(1)Al12 cuboctahedra, and faces with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra. All Zr(1)-Al(2) bond lengths are 2.75 Å. All Zr(1)-Al(3) bond lengths are 2.97 Å. Nb(1) is bonded to four equivalent Al(1) and eight equivalent Al(3) atoms to form NbAl12 cuboctahedra that share corners with four equivalent Nb(1)Al12 cuboctahedra, edges with eight equivalent Zr(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra. All Nb(1)-Al(1) bond lengths are 2.75 Å. All Nb(1)-Al(3) bond lengths are 2.90 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to four equivalent Nb(1) and eight equivalent Al(3) atoms to form AlNb4Al8 cuboctahedra that share corners with four equivalent Al(1)Nb4Al8 cuboctahedra, corners with eight equivalent Zr(1)Al12 cuboctahedra, edges with sixteen equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with two equivalent Zr(1)Al12 cuboctahedra, faces with four equivalent Nb(1)Al12 cuboctahedra, faces with four equivalent Al(1)Nb4Al8 cuboctahedra, and faces with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra. All Al(1)-Al(3) bond lengths are 2.90 Å. In the second Al site, Al(2) is bonded in a distorted square co-planar geometry to four equivalent Zr(1) and eight equivalent Al(3) atoms. All Al(2)-Al(3) bond lengths are 2.97 Å. In the third Al site, Al(3) is bonded to two equivalent Zr(1), two equivalent Nb(1), two equivalent Al(1), two equivalent Al(2), and four equivalent Al(3) atoms to form AlZr2Nb2Al8 cuboctahedra that share corners with twelve equivalent Al(3)Zr2Nb2Al8 cuboctahedra, edges with four equivalent Zr(1)Al12 cuboctahedra, edges with four equivalent Nb(1)Al12 cuboctahedra, edges with four equivalent Al(1)Nb4Al8 cuboctahedra, edges with eight equivalent Al(3)Zr2Nb2Al8 cuboctahedra, faces with two equivalent Zr(1)Al12 cuboctahedra, faces with two equivalent Nb(1)Al12 cuboctahedra, faces with two equivalent Al(1)Nb4Al8 cuboctahedra, and faces with ten equivalent Al(3)Zr2Nb2Al8 cuboctahedra. All Al(3)-Al(3) bond lengths are 2.75 Å.