Nd2ScNbO7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted NdO8 hexagonal bipyramids that share edges with two equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Sc(1)O6 octahedra, and edges with four equivalent Nb(1)O6 octahedra. In the second Nd site, Nd(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. Sc(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form ScO6 octahedra that share corners with two equivalent Sc(1)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, and edges with two equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 49-56°. Nb(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Sc(1)O6 octahedra, and edges with four equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-49°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Nd(1) and two equivalent Nd(2) atoms to form ONd4 tetrahedra that share corners with two equivalent O(3)Nd2Sc2 tetrahedra, corners with four equivalent O(1)Nd4 tetrahedra, corners with eight equivalent O(4)Nd2ScNb tetrahedra,  an edgeedge with one O(3)Nd2Sc2 tetrahedra, and edges with four equivalent O(4)Nd2ScNb tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Nd(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded to two equivalent Nd(2) and two equivalent Sc(1) atoms to form distorted ONd2Sc2 tetrahedra that share corners with two equivalent O(1)Nd4 tetrahedra, corners with four equivalent O(3)Nd2Sc2 tetrahedra, corners with eight equivalent O(4)Nd2ScNb tetrahedra,  an edgeedge with one O(1)Nd4 tetrahedra, and edges with four equivalent O(4)Nd2ScNb tetrahedra. In the fourth O site, O(4) is bonded to one Nd(1), one Nd(2), one Sc(1), and one Nb(1) atom to form distorted ONd2ScNb tetrahedra that share corners with two equivalent O(3)Nd2Sc2 tetrahedra, corners with two equivalent O(1)Nd4 tetrahedra, corners with eight equivalent O(4)Nd2ScNb tetrahedra,  an edgeedge with one O(3)Nd2Sc2 tetrahedra,  an edgeedge with one O(1)Nd4 tetrahedra, and edges with two equivalent O(4)Nd2ScNb tetrahedra.
Nd2ScNbO7 crystallizes in the orthorhombic Imma space group. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted NdO8 hexagonal bipyramids that share edges with two equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Sc(1)O6 octahedra, and edges with four equivalent Nb(1)O6 octahedra. Both Nd(1)-O(1) bond lengths are 2.28 Å. Both Nd(1)-O(2) bond lengths are 2.67 Å. All Nd(1)-O(4) bond lengths are 2.58 Å. In the second Nd site, Nd(2) is bonded in a body-centered cubic geometry to two equivalent O(1), two equivalent O(3), and four equivalent O(4) atoms. Both Nd(2)-O(1) bond lengths are 2.33 Å. Both Nd(2)-O(3) bond lengths are 2.53 Å. All Nd(2)-O(4) bond lengths are 2.63 Å. Sc(1) is bonded to two equivalent O(3) and four equivalent O(4) atoms to form ScO6 octahedra that share corners with two equivalent Sc(1)O6 octahedra, corners with four equivalent Nb(1)O6 octahedra, and edges with two equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 49-56°. Both Sc(1)-O(3) bond lengths are 2.12 Å. All Sc(1)-O(4) bond lengths are 2.14 Å. Nb(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Sc(1)O6 octahedra, and edges with four equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-49°. Both Nb(1)-O(2) bond lengths are 2.04 Å. All Nb(1)-O(4) bond lengths are 2.00 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Nd(1) and two equivalent Nd(2) atoms to form ONd4 tetrahedra that share corners with two equivalent O(3)Nd2Sc2 tetrahedra, corners with four equivalent O(1)Nd4 tetrahedra, corners with eight equivalent O(4)Nd2ScNb tetrahedra,  an edgeedge with one O(3)Nd2Sc2 tetrahedra, and edges with four equivalent O(4)Nd2ScNb tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Nd(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded to two equivalent Nd(2) and two equivalent Sc(1) atoms to form distorted ONd2Sc2 tetrahedra that share corners with two equivalent O(1)Nd4 tetrahedra, corners with four equivalent O(3)Nd2Sc2 tetrahedra, corners with eight equivalent O(4)Nd2ScNb tetrahedra,  an edgeedge with one O(1)Nd4 tetrahedra, and edges with four equivalent O(4)Nd2ScNb tetrahedra. In the fourth O site, O(4) is bonded to one Nd(1), one Nd(2), one Sc(1), and one Nb(1) atom to form distorted ONd2ScNb tetrahedra that share corners with two equivalent O(3)Nd2Sc2 tetrahedra, corners with two equivalent O(1)Nd4 tetrahedra, corners with eight equivalent O(4)Nd2ScNb tetrahedra,  an edgeedge with one O(3)Nd2Sc2 tetrahedra,  an edgeedge with one O(1)Nd4 tetrahedra, and edges with two equivalent O(4)Nd2ScNb tetrahedra.