ErNd3Fe34 crystallizes in the monoclinic Cm space group. Er(1) is bonded in a 19-coordinate geometry to one Fe(1), one Fe(17), one Fe(21), one Fe(22), one Fe(5), two equivalent Fe(10), two equivalent Fe(11), two equivalent Fe(13), two equivalent Fe(15), two equivalent Fe(8), and four equivalent Fe(19) atoms. There are three inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 19-coordinate geometry to one Fe(18), one Fe(2), one Fe(21), one Fe(22), one Fe(6), two equivalent Fe(12), two equivalent Fe(14), two equivalent Fe(16), two equivalent Fe(7), two equivalent Fe(9), and four equivalent Fe(20) atoms. In the second Nd site, Nd(2) is bonded in a 19-coordinate geometry to one Fe(17), one Fe(18), one Fe(21), one Fe(3), one Fe(5), two equivalent Fe(11), two equivalent Fe(13), two equivalent Fe(19), two equivalent Fe(7), two equivalent Fe(9), and four equivalent Fe(15) atoms. In the third Nd site, Nd(3) is bonded in a 19-coordinate geometry to one Fe(17), one Fe(18), one Fe(22), one Fe(4), one Fe(6), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(14), two equivalent Fe(20), two equivalent Fe(8), and four equivalent Fe(16) atoms. There are twenty-two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Er(1), one Fe(22), one Fe(4), one Fe(5), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(13), two equivalent Fe(19), and two equivalent Fe(8) atoms. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to one Nd(1), one Fe(21), one Fe(3), one Fe(6), two equivalent Fe(11), two equivalent Fe(14), two equivalent Fe(20), two equivalent Fe(7), and two equivalent Fe(9) atoms. In the third Fe site, Fe(3) is bonded in a 14-coordinate geometry to one Nd(2), one Fe(18), one Fe(2), one Fe(5), two equivalent Fe(11), two equivalent Fe(14), two equivalent Fe(15), two equivalent Fe(7), and two equivalent Fe(9) atoms. In the fourth Fe site, Fe(4) is bonded in a 14-coordinate geometry to one Nd(3), one Fe(1), one Fe(17), one Fe(6), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(13), two equivalent Fe(16), and two equivalent Fe(8) atoms. In the fifth Fe site, Fe(5) is bonded to one Er(1), one Nd(2), one Fe(1), one Fe(3), two equivalent Fe(11), two equivalent Fe(13), two equivalent Fe(15), and two equivalent Fe(19) atoms to form distorted FeNdErFe10 cuboctahedra that share corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with three equivalent Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, edges with two equivalent Fe(13)NdErFe10 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(13)NdErFe10 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra. In the sixth Fe site, Fe(6) is bonded to one Nd(1), one Nd(3), one Fe(2), one Fe(4), two equivalent Fe(12), two equivalent Fe(14), two equivalent Fe(16), and two equivalent Fe(20) atoms to form FeNd2Fe10 cuboctahedra that share corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with three equivalent Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra. In the seventh Fe site, Fe(7) is bonded to one Nd(1), one Nd(2), one Fe(11), one Fe(14), one Fe(15), one Fe(18), one Fe(2), one Fe(20), one Fe(21), one Fe(3), and two equivalent Fe(9) atoms to form FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(17)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(13)NdErFe10 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(13)NdErFe10 cuboctahedra, edges with two equivalent Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, and faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra. In the eighth Fe site, Fe(8) is bonded to one Er(1), one Nd(3), one Fe(1), one Fe(12), one Fe(13), one Fe(16), one Fe(17), one Fe(19), one Fe(22), one Fe(4), and two equivalent Fe(10) atoms to form FeNdErFe10 cuboctahedra that share  a cornercorner with one Fe(21)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(18)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(19)NdEr2Fe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(8)NdErFe10 cuboctahedra, and faces with three equivalent Fe(13)NdErFe10 cuboctahedra. In the ninth Fe site, Fe(9) is bonded to one Nd(1), one Nd(2), one Fe(11), one Fe(14), one Fe(15), one Fe(18), one Fe(2), one Fe(20), one Fe(21), one Fe(3), and two equivalent Fe(7) atoms to form distorted FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(17)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(16)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(19)NdEr2Fe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with three equivalent Fe(13)NdErFe10 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(9)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(19)NdEr2Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(18)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra. In the tenth Fe site, Fe(10) is bonded in a 12-coordinate geometry to one Er(1), one Nd(3), one Fe(1), one Fe(12), one Fe(13), one Fe(16), one Fe(17), one Fe(19), one Fe(22), one Fe(4), and two equivalent Fe(8) atoms. In the eleventh Fe site, Fe(11) is bonded in a 12-coordinate geometry to one Er(1), one Nd(2), one Fe(11), one Fe(19), one Fe(2), one Fe(21), one Fe(3), one Fe(5), one Fe(7), one Fe(9), and two equivalent Fe(15) atoms. In the twelfth Fe site, Fe(12) is bonded in a 12-coordinate geometry to one Nd(1), one Nd(3), one Fe(1), one Fe(10), one Fe(12), one Fe(20), one Fe(22), one Fe(4), one Fe(6), one Fe(8), and two equivalent Fe(16) atoms. In the thirteenth Fe site, Fe(13) is bonded to one Er(1), one Nd(2), one Fe(1), one Fe(10), one Fe(13), one Fe(15), one Fe(17), one Fe(4), one Fe(5), one Fe(8), and two equivalent Fe(19) atoms to form distorted FeNdErFe10 cuboctahedra that share  a cornercorner with one Fe(21)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(7)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(16)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with three equivalent Fe(13)NdErFe10 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(13)NdErFe10 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, faces with three equivalent Fe(8)NdErFe10 cuboctahedra, and faces with four equivalent Fe(19)NdEr2Fe9 cuboctahedra. In the fourteenth Fe site, Fe(14) is bonded in a 12-coordinate geometry to one Nd(1), one Nd(3), one Fe(14), one Fe(16), one Fe(18), one Fe(2), one Fe(3), one Fe(6), one Fe(7), one Fe(9), and two equivalent Fe(20) atoms. In the fifteenth Fe site, Fe(15) is bonded to one Er(1), two equivalent Nd(2), one Fe(13), one Fe(19), one Fe(21), one Fe(3), one Fe(5), one Fe(7), one Fe(9), and two equivalent Fe(11) atoms to form FeNd2ErFe9 cuboctahedra that share  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(9)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(13)NdErFe10 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, and faces with two equivalent Fe(13)NdErFe10 cuboctahedra. In the sixteenth Fe site, Fe(16) is bonded to one Nd(1), two equivalent Nd(3), one Fe(10), one Fe(14), one Fe(20), one Fe(22), one Fe(4), one Fe(6), one Fe(8), and two equivalent Fe(12) atoms to form FeNd3Fe9 cuboctahedra that share  a cornercorner with one Fe(21)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(9)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(13)NdErFe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra. In the seventeenth Fe site, Fe(17) is bonded to one Er(1), one Nd(2), one Nd(3), one Fe(4), two equivalent Fe(10), two equivalent Fe(13), two equivalent Fe(19), and two equivalent Fe(8) atoms to form FeNd2ErFe9 cuboctahedra that share corners with two equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with three equivalent Fe(5)NdErFe10 cuboctahedra, corners with four equivalent Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(8)NdErFe10 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(8)NdErFe10 cuboctahedra, and faces with four equivalent Fe(13)NdErFe10 cuboctahedra. In the eighteenth Fe site, Fe(18) is bonded to one Nd(1), one Nd(2), one Nd(3), one Fe(3), two equivalent Fe(14), two equivalent Fe(20), two equivalent Fe(7), and two equivalent Fe(9) atoms to form FeNd3Fe9 cuboctahedra that share corners with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, and faces with four equivalent Fe(9)Nd2Fe10 cuboctahedra. In the nineteenth Fe site, Fe(19) is bonded to two equivalent Er(1), one Nd(2), one Fe(1), one Fe(10), one Fe(11), one Fe(15), one Fe(17), one Fe(5), one Fe(8), and two equivalent Fe(13) atoms to form FeNdEr2Fe9 cuboctahedra that share  a cornercorner with one Fe(9)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(18)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(8)NdErFe10 cuboctahedra, and faces with four equivalent Fe(13)NdErFe10 cuboctahedra. In the twentieth Fe site, Fe(20) is bonded to one Nd(3), two equivalent Nd(1), one Fe(12), one Fe(16), one Fe(18), one Fe(2), one Fe(6), one Fe(7), one Fe(9), and two equivalent Fe(14) atoms to form FeNd3Fe9 cuboctahedra that share  a cornercorner with one Fe(17)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(9)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra. In the twenty-first Fe site, Fe(21) is bonded to one Er(1), one Nd(1), one Nd(2), one Fe(2), two equivalent Fe(11), two equivalent Fe(15), two equivalent Fe(7), and two equivalent Fe(9) atoms to form FeNd2ErFe9 cuboctahedra that share corners with two equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(5)NdErFe10 cuboctahedra, corners with four equivalent Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, edges with two equivalent Fe(13)NdErFe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, and faces with four equivalent Fe(9)Nd2Fe10 cuboctahedra. In the twenty-second Fe site, Fe(22) is bonded to one Er(1), one Nd(1), one Nd(3), one Fe(1), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(16), and two equivalent Fe(8) atoms to form FeNd2ErFe9 cuboctahedra that share corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with three equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, edges with two equivalent Fe(8)NdErFe10 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(13)NdErFe10 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra.
ErNd3Fe34 crystallizes in the monoclinic Cm space group. Er(1) is bonded in a 19-coordinate geometry to one Fe(1), one Fe(17), one Fe(21), one Fe(22), one Fe(5), two equivalent Fe(10), two equivalent Fe(11), two equivalent Fe(13), two equivalent Fe(15), two equivalent Fe(8), and four equivalent Fe(19) atoms. The Er(1)-Fe(1) bond length is 3.02 Å. The Er(1)-Fe(17) bond length is 3.04 Å. The Er(1)-Fe(21) bond length is 3.19 Å. The Er(1)-Fe(22) bond length is 3.15 Å. The Er(1)-Fe(5) bond length is 3.28 Å. Both Er(1)-Fe(10) bond lengths are 3.00 Å. Both Er(1)-Fe(11) bond lengths are 3.02 Å. Both Er(1)-Fe(13) bond lengths are 3.03 Å. Both Er(1)-Fe(15) bond lengths are 3.07 Å. Both Er(1)-Fe(8) bond lengths are 3.25 Å. There are two shorter (3.17 Å) and two longer (3.24 Å) Er(1)-Fe(19) bond lengths. There are three inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 19-coordinate geometry to one Fe(18), one Fe(2), one Fe(21), one Fe(22), one Fe(6), two equivalent Fe(12), two equivalent Fe(14), two equivalent Fe(16), two equivalent Fe(7), two equivalent Fe(9), and four equivalent Fe(20) atoms. The Nd(1)-Fe(18) bond length is 3.08 Å. The Nd(1)-Fe(2) bond length is 3.05 Å. The Nd(1)-Fe(21) bond length is 3.20 Å. The Nd(1)-Fe(22) bond length is 3.27 Å. The Nd(1)-Fe(6) bond length is 3.29 Å. Both Nd(1)-Fe(12) bond lengths are 3.06 Å. Both Nd(1)-Fe(14) bond lengths are 3.02 Å. Both Nd(1)-Fe(16) bond lengths are 3.09 Å. Both Nd(1)-Fe(7) bond lengths are 3.27 Å. Both Nd(1)-Fe(9) bond lengths are 3.08 Å. There are two shorter (3.18 Å) and two longer (3.23 Å) Nd(1)-Fe(20) bond lengths. In the second Nd site, Nd(2) is bonded in a 19-coordinate geometry to one Fe(17), one Fe(18), one Fe(21), one Fe(3), one Fe(5), two equivalent Fe(11), two equivalent Fe(13), two equivalent Fe(19), two equivalent Fe(7), two equivalent Fe(9), and four equivalent Fe(15) atoms. The Nd(2)-Fe(17) bond length is 3.18 Å. The Nd(2)-Fe(18) bond length is 3.18 Å. The Nd(2)-Fe(21) bond length is 3.09 Å. The Nd(2)-Fe(3) bond length is 3.06 Å. The Nd(2)-Fe(5) bond length is 3.29 Å. Both Nd(2)-Fe(11) bond lengths are 3.13 Å. Both Nd(2)-Fe(13) bond lengths are 3.03 Å. Both Nd(2)-Fe(19) bond lengths are 3.04 Å. Both Nd(2)-Fe(7) bond lengths are 3.28 Å. Both Nd(2)-Fe(9) bond lengths are 3.02 Å. There are two shorter (3.17 Å) and two longer (3.24 Å) Nd(2)-Fe(15) bond lengths. In the third Nd site, Nd(3) is bonded in a 19-coordinate geometry to one Fe(17), one Fe(18), one Fe(22), one Fe(4), one Fe(6), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(14), two equivalent Fe(20), two equivalent Fe(8), and four equivalent Fe(16) atoms. The Nd(3)-Fe(17) bond length is 3.20 Å. The Nd(3)-Fe(18) bond length is 3.25 Å. The Nd(3)-Fe(22) bond length is 3.09 Å. The Nd(3)-Fe(4) bond length is 3.05 Å. The Nd(3)-Fe(6) bond length is 3.27 Å. Both Nd(3)-Fe(10) bond lengths are 3.04 Å. Both Nd(3)-Fe(12) bond lengths are 3.03 Å. Both Nd(3)-Fe(14) bond lengths are 3.05 Å. Both Nd(3)-Fe(20) bond lengths are 3.09 Å. Both Nd(3)-Fe(8) bond lengths are 3.29 Å. There are two shorter (3.18 Å) and two longer (3.23 Å) Nd(3)-Fe(16) bond lengths. There are twenty-two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 14-coordinate geometry to one Er(1), one Fe(22), one Fe(4), one Fe(5), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(13), two equivalent Fe(19), and two equivalent Fe(8) atoms. The Fe(1)-Fe(22) bond length is 2.63 Å. The Fe(1)-Fe(4) bond length is 2.40 Å. The Fe(1)-Fe(5) bond length is 2.60 Å. Both Fe(1)-Fe(10) bond lengths are 2.75 Å. Both Fe(1)-Fe(12) bond lengths are 2.75 Å. Both Fe(1)-Fe(13) bond lengths are 2.73 Å. Both Fe(1)-Fe(19) bond lengths are 2.62 Å. Both Fe(1)-Fe(8) bond lengths are 2.59 Å. In the second Fe site, Fe(2) is bonded in a 14-coordinate geometry to one Nd(1), one Fe(21), one Fe(3), one Fe(6), two equivalent Fe(11), two equivalent Fe(14), two equivalent Fe(20), two equivalent Fe(7), and two equivalent Fe(9) atoms. The Fe(2)-Fe(21) bond length is 2.65 Å. The Fe(2)-Fe(3) bond length is 2.37 Å. The Fe(2)-Fe(6) bond length is 2.58 Å. Both Fe(2)-Fe(11) bond lengths are 2.68 Å. Both Fe(2)-Fe(14) bond lengths are 2.72 Å. Both Fe(2)-Fe(20) bond lengths are 2.61 Å. Both Fe(2)-Fe(7) bond lengths are 2.61 Å. Both Fe(2)-Fe(9) bond lengths are 2.72 Å. In the third Fe site, Fe(3) is bonded in a 14-coordinate geometry to one Nd(2), one Fe(18), one Fe(2), one Fe(5), two equivalent Fe(11), two equivalent Fe(14), two equivalent Fe(15), two equivalent Fe(7), and two equivalent Fe(9) atoms. The Fe(3)-Fe(18) bond length is 2.59 Å. The Fe(3)-Fe(5) bond length is 2.61 Å. Both Fe(3)-Fe(11) bond lengths are 2.71 Å. Both Fe(3)-Fe(14) bond lengths are 2.71 Å. Both Fe(3)-Fe(15) bond lengths are 2.64 Å. Both Fe(3)-Fe(7) bond lengths are 2.60 Å. Both Fe(3)-Fe(9) bond lengths are 2.70 Å. In the fourth Fe site, Fe(4) is bonded in a 14-coordinate geometry to one Nd(3), one Fe(1), one Fe(17), one Fe(6), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(13), two equivalent Fe(16), and two equivalent Fe(8) atoms. The Fe(4)-Fe(17) bond length is 2.66 Å. The Fe(4)-Fe(6) bond length is 2.62 Å. Both Fe(4)-Fe(10) bond lengths are 2.75 Å. Both Fe(4)-Fe(12) bond lengths are 2.74 Å. Both Fe(4)-Fe(13) bond lengths are 2.72 Å. Both Fe(4)-Fe(16) bond lengths are 2.63 Å. Both Fe(4)-Fe(8) bond lengths are 2.61 Å. In the fifth Fe site, Fe(5) is bonded to one Er(1), one Nd(2), one Fe(1), one Fe(3), two equivalent Fe(11), two equivalent Fe(13), two equivalent Fe(15), and two equivalent Fe(19) atoms to form distorted FeNdErFe10 cuboctahedra that share corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with three equivalent Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, edges with two equivalent Fe(13)NdErFe10 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(13)NdErFe10 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra. Both Fe(5)-Fe(11) bond lengths are 2.37 Å. Both Fe(5)-Fe(13) bond lengths are 2.44 Å. Both Fe(5)-Fe(15) bond lengths are 2.44 Å. Both Fe(5)-Fe(19) bond lengths are 2.42 Å. In the sixth Fe site, Fe(6) is bonded to one Nd(1), one Nd(3), one Fe(2), one Fe(4), two equivalent Fe(12), two equivalent Fe(14), two equivalent Fe(16), and two equivalent Fe(20) atoms to form FeNd2Fe10 cuboctahedra that share corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with three equivalent Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra. Both Fe(6)-Fe(12) bond lengths are 2.43 Å. Both Fe(6)-Fe(14) bond lengths are 2.43 Å. Both Fe(6)-Fe(16) bond lengths are 2.45 Å. Both Fe(6)-Fe(20) bond lengths are 2.46 Å. In the seventh Fe site, Fe(7) is bonded to one Nd(1), one Nd(2), one Fe(11), one Fe(14), one Fe(15), one Fe(18), one Fe(2), one Fe(20), one Fe(21), one Fe(3), and two equivalent Fe(9) atoms to form FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(17)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(13)NdErFe10 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(13)NdErFe10 cuboctahedra, edges with two equivalent Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, and faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra. The Fe(7)-Fe(11) bond length is 2.42 Å. The Fe(7)-Fe(14) bond length is 2.44 Å. The Fe(7)-Fe(15) bond length is 2.43 Å. The Fe(7)-Fe(18) bond length is 2.46 Å. The Fe(7)-Fe(20) bond length is 2.44 Å. The Fe(7)-Fe(21) bond length is 2.43 Å. There is one shorter (2.42 Å) and one longer (2.43 Å) Fe(7)-Fe(9) bond length. In the eighth Fe site, Fe(8) is bonded to one Er(1), one Nd(3), one Fe(1), one Fe(12), one Fe(13), one Fe(16), one Fe(17), one Fe(19), one Fe(22), one Fe(4), and two equivalent Fe(10) atoms to form FeNdErFe10 cuboctahedra that share  a cornercorner with one Fe(21)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(18)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(19)NdEr2Fe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(8)NdErFe10 cuboctahedra, and faces with three equivalent Fe(13)NdErFe10 cuboctahedra. The Fe(8)-Fe(12) bond length is 2.43 Å. The Fe(8)-Fe(13) bond length is 2.41 Å. The Fe(8)-Fe(16) bond length is 2.46 Å. The Fe(8)-Fe(17) bond length is 2.46 Å. The Fe(8)-Fe(19) bond length is 2.45 Å. The Fe(8)-Fe(22) bond length is 2.44 Å. Both Fe(8)-Fe(10) bond lengths are 2.43 Å. In the ninth Fe site, Fe(9) is bonded to one Nd(1), one Nd(2), one Fe(11), one Fe(14), one Fe(15), one Fe(18), one Fe(2), one Fe(20), one Fe(21), one Fe(3), and two equivalent Fe(7) atoms to form distorted FeNd2Fe10 cuboctahedra that share  a cornercorner with one Fe(17)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(16)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(19)NdEr2Fe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with three equivalent Fe(13)NdErFe10 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(9)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(19)NdEr2Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(18)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra. The Fe(9)-Fe(11) bond length is 2.44 Å. The Fe(9)-Fe(14) bond length is 2.48 Å. The Fe(9)-Fe(15) bond length is 2.50 Å. The Fe(9)-Fe(18) bond length is 2.66 Å. The Fe(9)-Fe(20) bond length is 2.55 Å. The Fe(9)-Fe(21) bond length is 2.66 Å. In the tenth Fe site, Fe(10) is bonded in a 12-coordinate geometry to one Er(1), one Nd(3), one Fe(1), one Fe(12), one Fe(13), one Fe(16), one Fe(17), one Fe(19), one Fe(22), one Fe(4), and two equivalent Fe(8) atoms. The Fe(10)-Fe(12) bond length is 2.48 Å. The Fe(10)-Fe(13) bond length is 2.44 Å. The Fe(10)-Fe(16) bond length is 2.54 Å. The Fe(10)-Fe(17) bond length is 2.61 Å. The Fe(10)-Fe(19) bond length is 2.54 Å. The Fe(10)-Fe(22) bond length is 2.62 Å. In the eleventh Fe site, Fe(11) is bonded in a 12-coordinate geometry to one Er(1), one Nd(2), one Fe(11), one Fe(19), one Fe(2), one Fe(21), one Fe(3), one Fe(5), one Fe(7), one Fe(9), and two equivalent Fe(15) atoms. The Fe(11)-Fe(11) bond length is 2.27 Å. The Fe(11)-Fe(19) bond length is 2.65 Å. The Fe(11)-Fe(21) bond length is 2.45 Å. There is one shorter (2.58 Å) and one longer (2.67 Å) Fe(11)-Fe(15) bond length. In the twelfth Fe site, Fe(12) is bonded in a 12-coordinate geometry to one Nd(1), one Nd(3), one Fe(1), one Fe(10), one Fe(12), one Fe(20), one Fe(22), one Fe(4), one Fe(6), one Fe(8), and two equivalent Fe(16) atoms. The Fe(12)-Fe(12) bond length is 2.46 Å. The Fe(12)-Fe(20) bond length is 2.66 Å. The Fe(12)-Fe(22) bond length is 2.55 Å. There is one shorter (2.53 Å) and one longer (2.64 Å) Fe(12)-Fe(16) bond length. In the thirteenth Fe site, Fe(13) is bonded to one Er(1), one Nd(2), one Fe(1), one Fe(10), one Fe(13), one Fe(15), one Fe(17), one Fe(4), one Fe(5), one Fe(8), and two equivalent Fe(19) atoms to form distorted FeNdErFe10 cuboctahedra that share  a cornercorner with one Fe(21)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(7)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(16)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with three equivalent Fe(13)NdErFe10 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(13)NdErFe10 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, faces with three equivalent Fe(8)NdErFe10 cuboctahedra, and faces with four equivalent Fe(19)NdEr2Fe9 cuboctahedra. The Fe(13)-Fe(13) bond length is 2.47 Å. The Fe(13)-Fe(15) bond length is 2.61 Å. The Fe(13)-Fe(17) bond length is 2.55 Å. There is one shorter (2.52 Å) and one longer (2.65 Å) Fe(13)-Fe(19) bond length. In the fourteenth Fe site, Fe(14) is bonded in a 12-coordinate geometry to one Nd(1), one Nd(3), one Fe(14), one Fe(16), one Fe(18), one Fe(2), one Fe(3), one Fe(6), one Fe(7), one Fe(9), and two equivalent Fe(20) atoms. The Fe(14)-Fe(14) bond length is 2.48 Å. The Fe(14)-Fe(16) bond length is 2.64 Å. The Fe(14)-Fe(18) bond length is 2.54 Å. There is one shorter (2.53 Å) and one longer (2.63 Å) Fe(14)-Fe(20) bond length. In the fifteenth Fe site, Fe(15) is bonded to one Er(1), two equivalent Nd(2), one Fe(13), one Fe(19), one Fe(21), one Fe(3), one Fe(5), one Fe(7), one Fe(9), and two equivalent Fe(11) atoms to form FeNd2ErFe9 cuboctahedra that share  a cornercorner with one Fe(22)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(9)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(13)NdErFe10 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, and faces with two equivalent Fe(13)NdErFe10 cuboctahedra. The Fe(15)-Fe(19) bond length is 2.46 Å. The Fe(15)-Fe(21) bond length is 2.48 Å. In the sixteenth Fe site, Fe(16) is bonded to one Nd(1), two equivalent Nd(3), one Fe(10), one Fe(14), one Fe(20), one Fe(22), one Fe(4), one Fe(6), one Fe(8), and two equivalent Fe(12) atoms to form FeNd3Fe9 cuboctahedra that share  a cornercorner with one Fe(21)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(9)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(13)NdErFe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra. The Fe(16)-Fe(20) bond length is 2.51 Å. The Fe(16)-Fe(22) bond length is 2.49 Å. In the seventeenth Fe site, Fe(17) is bonded to one Er(1), one Nd(2), one Nd(3), one Fe(4), two equivalent Fe(10), two equivalent Fe(13), two equivalent Fe(19), and two equivalent Fe(8) atoms to form FeNd2ErFe9 cuboctahedra that share corners with two equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with three equivalent Fe(5)NdErFe10 cuboctahedra, corners with four equivalent Fe(19)NdEr2Fe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(8)NdErFe10 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(8)NdErFe10 cuboctahedra, and faces with four equivalent Fe(13)NdErFe10 cuboctahedra. Both Fe(17)-Fe(19) bond lengths are 2.49 Å. In the eighteenth Fe site, Fe(18) is bonded to one Nd(1), one Nd(2), one Nd(3), one Fe(3), two equivalent Fe(14), two equivalent Fe(20), two equivalent Fe(7), and two equivalent Fe(9) atoms to form FeNd3Fe9 cuboctahedra that share corners with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(20)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra, edges with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(16)Nd3Fe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, and faces with four equivalent Fe(9)Nd2Fe10 cuboctahedra. Both Fe(18)-Fe(20) bond lengths are 2.48 Å. In the nineteenth Fe site, Fe(19) is bonded to two equivalent Er(1), one Nd(2), one Fe(1), one Fe(10), one Fe(11), one Fe(15), one Fe(17), one Fe(5), one Fe(8), and two equivalent Fe(13) atoms to form FeNdEr2Fe9 cuboctahedra that share  a cornercorner with one Fe(9)Nd2Fe10 cuboctahedra,  a cornercorner with one Fe(18)Nd3Fe9 cuboctahedra,  a cornercorner with one Fe(5)NdErFe10 cuboctahedra, corners with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(9)Nd2Fe10 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(8)NdErFe10 cuboctahedra, and faces with four equivalent Fe(13)NdErFe10 cuboctahedra. In the twentieth Fe site, Fe(20) is bonded to one Nd(3), two equivalent Nd(1), one Fe(12), one Fe(16), one Fe(18), one Fe(2), one Fe(6), one Fe(7), one Fe(9), and two equivalent Fe(14) atoms to form FeNd3Fe9 cuboctahedra that share  a cornercorner with one Fe(17)Nd2ErFe9 cuboctahedra,  a cornercorner with one Fe(6)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(20)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(21)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(22)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(7)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(9)Nd2Fe10 cuboctahedra,  an edgeedge with one Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(8)NdErFe10 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra,  a faceface with one Fe(21)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(22)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(9)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, and faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra. In the twenty-first Fe site, Fe(21) is bonded to one Er(1), one Nd(1), one Nd(2), one Fe(2), two equivalent Fe(11), two equivalent Fe(15), two equivalent Fe(7), and two equivalent Fe(9) atoms to form FeNd2ErFe9 cuboctahedra that share corners with two equivalent Fe(22)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(16)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(18)Nd3Fe9 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with two equivalent Fe(8)NdErFe10 cuboctahedra, corners with three equivalent Fe(5)NdErFe10 cuboctahedra, corners with four equivalent Fe(15)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(17)Nd2ErFe9 cuboctahedra,  an edgeedge with one Fe(6)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(7)Nd2Fe10 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, edges with two equivalent Fe(13)NdErFe10 cuboctahedra,  a faceface with one Fe(18)Nd3Fe9 cuboctahedra,  a faceface with one Fe(5)NdErFe10 cuboctahedra, faces with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, faces with two equivalent Fe(7)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, and faces with four equivalent Fe(9)Nd2Fe10 cuboctahedra. In the twenty-second Fe site, Fe(22) is bonded to one Er(1), one Nd(1), one Nd(3), one Fe(1), two equivalent Fe(10), two equivalent Fe(12), two equivalent Fe(16), and two equivalent Fe(8) atoms to form FeNd2ErFe9 cuboctahedra that share corners with two equivalent Fe(15)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(17)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(21)Nd2ErFe9 cuboctahedra, corners with two equivalent Fe(7)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(9)Nd2Fe10 cuboctahedra, corners with two equivalent Fe(13)NdErFe10 cuboctahedra, corners with three equivalent Fe(6)Nd2Fe10 cuboctahedra, corners with four equivalent Fe(16)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(18)Nd3Fe9 cuboctahedra,  an edgeedge with one Fe(5)NdErFe10 cuboctahedra, edges with two equivalent Fe(20)Nd3Fe9 cuboctahedra, edges with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, edges with two equivalent Fe(8)NdErFe10 cuboctahedra,  a faceface with one Fe(17)Nd2ErFe9 cuboctahedra,  a faceface with one Fe(6)Nd2Fe10 cuboctahedra, faces with two equivalent Fe(16)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(20)Nd3Fe9 cuboctahedra, faces with two equivalent Fe(19)NdEr2Fe9 cuboctahedra, faces with two equivalent Fe(13)NdErFe10 cuboctahedra, and faces with two equivalent Fe(8)NdErFe10 cuboctahedra.