CaNdAl3O7 crystallizes in the orthorhombic Cmm2 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(3), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Nd(1) is bonded in a 8-coordinate geometry to one O(4), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(6), and two equivalent O(1) atoms to form corner-sharing AlO4 tetrahedra. In the second Al site, Al(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. In the third Al site, Al(3) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded to two equivalent Ca(1) and two equivalent Al(2) atoms to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(4)Ca2NdAl tetrahedra, corners with two equivalent O(3)CaNd2Al tetrahedra, and edges with two equivalent O(4)Ca2NdAl tetrahedra. In the second O site, O(6) is bonded to two equivalent Nd(1) and two equivalent Al(1) atoms to form distorted ONd2Al2 tetrahedra that share corners with two equivalent O(4)Ca2NdAl tetrahedra, corners with two equivalent O(3)CaNd2Al tetrahedra, and edges with two equivalent O(3)CaNd2Al tetrahedra. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Nd(1), one Al(1), and one Al(3) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Nd(1), one Al(2), and one Al(3) atom. In the fifth O site, O(3) is bonded to one Ca(1), two equivalent Nd(1), and one Al(1) atom to form distorted OCaNd2Al tetrahedra that share  a cornercorner with one O(5)Ca2Al2 tetrahedra,  a cornercorner with one O(6)Nd2Al2 tetrahedra, corners with four equivalent O(4)Ca2NdAl tetrahedra,  an edgeedge with one O(3)CaNd2Al tetrahedra, and  an edgeedge with one O(6)Nd2Al2 tetrahedra. In the sixth O site, O(4) is bonded to two equivalent Ca(1), one Nd(1), and one Al(2) atom to form distorted OCa2NdAl tetrahedra that share  a cornercorner with one O(5)Ca2Al2 tetrahedra,  a cornercorner with one O(6)Nd2Al2 tetrahedra, corners with four equivalent O(3)CaNd2Al tetrahedra,  an edgeedge with one O(5)Ca2Al2 tetrahedra, and  an edgeedge with one O(4)Ca2NdAl tetrahedra.
CaNdAl3O7 crystallizes in the orthorhombic Cmm2 space group. Ca(1) is bonded in a 8-coordinate geometry to one O(3), one O(5), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The Ca(1)-O(3) bond length is 2.50 Å. The Ca(1)-O(5) bond length is 2.44 Å. Both Ca(1)-O(1) bond lengths are 2.47 Å. Both Ca(1)-O(2) bond lengths are 2.95 Å. Both Ca(1)-O(4) bond lengths are 2.58 Å. Nd(1) is bonded in a 8-coordinate geometry to one O(4), one O(6), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Nd(1)-O(4) bond length is 2.40 Å. The Nd(1)-O(6) bond length is 2.46 Å. Both Nd(1)-O(1) bond lengths are 2.85 Å. Both Nd(1)-O(2) bond lengths are 2.44 Å. Both Nd(1)-O(3) bond lengths are 2.56 Å. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(3), one O(6), and two equivalent O(1) atoms to form corner-sharing AlO4 tetrahedra. The Al(1)-O(3) bond length is 1.75 Å. The Al(1)-O(6) bond length is 1.77 Å. Both Al(1)-O(1) bond lengths are 1.77 Å. In the second Al site, Al(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. The Al(2)-O(4) bond length is 1.74 Å. The Al(2)-O(5) bond length is 1.75 Å. Both Al(2)-O(2) bond lengths are 1.78 Å. In the third Al site, Al(3) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form corner-sharing AlO4 tetrahedra. Both Al(3)-O(1) bond lengths are 1.77 Å. Both Al(3)-O(2) bond lengths are 1.77 Å. There are six inequivalent O sites. In the first O site, O(5) is bonded to two equivalent Ca(1) and two equivalent Al(2) atoms to form distorted OCa2Al2 tetrahedra that share corners with two equivalent O(4)Ca2NdAl tetrahedra, corners with two equivalent O(3)CaNd2Al tetrahedra, and edges with two equivalent O(4)Ca2NdAl tetrahedra. In the second O site, O(6) is bonded to two equivalent Nd(1) and two equivalent Al(1) atoms to form distorted ONd2Al2 tetrahedra that share corners with two equivalent O(4)Ca2NdAl tetrahedra, corners with two equivalent O(3)CaNd2Al tetrahedra, and edges with two equivalent O(3)CaNd2Al tetrahedra. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Nd(1), one Al(1), and one Al(3) atom. In the fourth O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Nd(1), one Al(2), and one Al(3) atom. In the fifth O site, O(3) is bonded to one Ca(1), two equivalent Nd(1), and one Al(1) atom to form distorted OCaNd2Al tetrahedra that share  a cornercorner with one O(5)Ca2Al2 tetrahedra,  a cornercorner with one O(6)Nd2Al2 tetrahedra, corners with four equivalent O(4)Ca2NdAl tetrahedra,  an edgeedge with one O(3)CaNd2Al tetrahedra, and  an edgeedge with one O(6)Nd2Al2 tetrahedra. In the sixth O site, O(4) is bonded to two equivalent Ca(1), one Nd(1), and one Al(2) atom to form distorted OCa2NdAl tetrahedra that share  a cornercorner with one O(5)Ca2Al2 tetrahedra,  a cornercorner with one O(6)Nd2Al2 tetrahedra, corners with four equivalent O(3)CaNd2Al tetrahedra,  an edgeedge with one O(5)Ca2Al2 tetrahedra, and  an edgeedge with one O(4)Ca2NdAl tetrahedra.