Nd7VO4Se8 crystallizes in the orthorhombic Pbam space group. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 3-coordinate geometry to one Se(2), two equivalent Se(1), two equivalent Se(3), one O(1), and two equivalent O(2) atoms. In the second Nd site, Nd(2) is bonded in a 3-coordinate geometry to one Se(1), two equivalent Se(2), two equivalent Se(4), one O(2), and two equivalent O(1) atoms. In the third Nd site, Nd(3) is bonded to two equivalent Se(4) and four equivalent Se(3) atoms to form edge-sharing NdSe6 octahedra. In the fourth Nd site, Nd(4) is bonded in a 7-coordinate geometry to one Se(1), one Se(3), two equivalent Se(2), two equivalent Se(4), and one O(2) atom. V(1) is bonded in a distorted linear geometry to four equivalent Se(1) and two equivalent O(1) atoms. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one Nd(2), one Nd(4), two equivalent Nd(1), and two equivalent V(1) atoms. In the second Se site, Se(2) is bonded to one Nd(1), two equivalent Nd(2), and two equivalent Nd(4) atoms to form distorted SeNd5 trigonal bipyramids that share corners with four equivalent Se(3)Nd5 square pyramids, corners with two equivalent O(2)Nd4 tetrahedra, corners with three equivalent O(1)Nd3V tetrahedra,  an edgeedge with one O(1)Nd3V tetrahedra, edges with two equivalent O(2)Nd4 tetrahedra, and edges with two equivalent Se(2)Nd5 trigonal bipyramids. In the third Se site, Se(3) is bonded to one Nd(4), two equivalent Nd(1), and two equivalent Nd(3) atoms to form SeNd5 square pyramids that share corners with two equivalent Se(3)Nd5 square pyramids, corners with two equivalent O(1)Nd3V tetrahedra, corners with three equivalent O(2)Nd4 tetrahedra, corners with four equivalent Se(2)Nd5 trigonal bipyramids, edges with three equivalent Se(3)Nd5 square pyramids, and  an edgeedge with one O(2)Nd4 tetrahedra. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to one Nd(3), two equivalent Nd(2), and two equivalent Nd(4) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Nd(1), two equivalent Nd(2), and one V(1) atom to form ONd3V tetrahedra that share corners with two equivalent Se(3)Nd5 square pyramids, corners with three equivalent O(1)Nd3V tetrahedra, corners with three equivalent Se(2)Nd5 trigonal bipyramids, edges with two equivalent O(2)Nd4 tetrahedra, and  an edgeedge with one Se(2)Nd5 trigonal bipyramid. In the second O site, O(2) is bonded to one Nd(2), one Nd(4), and two equivalent Nd(1) atoms to form ONd4 tetrahedra that share corners with three equivalent Se(3)Nd5 square pyramids, corners with two equivalent O(2)Nd4 tetrahedra, corners with two equivalent Se(2)Nd5 trigonal bipyramids,  an edgeedge with one Se(3)Nd5 square pyramid, edges with two equivalent O(1)Nd3V tetrahedra, and edges with two equivalent Se(2)Nd5 trigonal bipyramids.
Nd7VO4Se8 crystallizes in the orthorhombic Pbam space group. There are four inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 3-coordinate geometry to one Se(2), two equivalent Se(1), two equivalent Se(3), one O(1), and two equivalent O(2) atoms. The Nd(1)-Se(2) bond length is 3.03 Å. Both Nd(1)-Se(1) bond lengths are 3.39 Å. Both Nd(1)-Se(3) bond lengths are 3.25 Å. The Nd(1)-O(1) bond length is 2.38 Å. Both Nd(1)-O(2) bond lengths are 2.37 Å. In the second Nd site, Nd(2) is bonded in a 3-coordinate geometry to one Se(1), two equivalent Se(2), two equivalent Se(4), one O(2), and two equivalent O(1) atoms. The Nd(2)-Se(1) bond length is 3.08 Å. Both Nd(2)-Se(2) bond lengths are 3.19 Å. Both Nd(2)-Se(4) bond lengths are 3.12 Å. The Nd(2)-O(2) bond length is 2.40 Å. Both Nd(2)-O(1) bond lengths are 2.38 Å. In the third Nd site, Nd(3) is bonded to two equivalent Se(4) and four equivalent Se(3) atoms to form edge-sharing NdSe6 octahedra. Both Nd(3)-Se(4) bond lengths are 2.92 Å. All Nd(3)-Se(3) bond lengths are 2.96 Å. In the fourth Nd site, Nd(4) is bonded in a 7-coordinate geometry to one Se(1), one Se(3), two equivalent Se(2), two equivalent Se(4), and one O(2) atom. The Nd(4)-Se(1) bond length is 3.15 Å. The Nd(4)-Se(3) bond length is 3.23 Å. Both Nd(4)-Se(2) bond lengths are 2.94 Å. Both Nd(4)-Se(4) bond lengths are 2.97 Å. The Nd(4)-O(2) bond length is 2.44 Å. V(1) is bonded in a distorted linear geometry to four equivalent Se(1) and two equivalent O(1) atoms. All V(1)-Se(1) bond lengths are 2.70 Å. Both V(1)-O(1) bond lengths are 1.98 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to one Nd(2), one Nd(4), two equivalent Nd(1), and two equivalent V(1) atoms. In the second Se site, Se(2) is bonded to one Nd(1), two equivalent Nd(2), and two equivalent Nd(4) atoms to form distorted SeNd5 trigonal bipyramids that share corners with four equivalent Se(3)Nd5 square pyramids, corners with two equivalent O(2)Nd4 tetrahedra, corners with three equivalent O(1)Nd3V tetrahedra,  an edgeedge with one O(1)Nd3V tetrahedra, edges with two equivalent O(2)Nd4 tetrahedra, and edges with two equivalent Se(2)Nd5 trigonal bipyramids. In the third Se site, Se(3) is bonded to one Nd(4), two equivalent Nd(1), and two equivalent Nd(3) atoms to form SeNd5 square pyramids that share corners with two equivalent Se(3)Nd5 square pyramids, corners with two equivalent O(1)Nd3V tetrahedra, corners with three equivalent O(2)Nd4 tetrahedra, corners with four equivalent Se(2)Nd5 trigonal bipyramids, edges with three equivalent Se(3)Nd5 square pyramids, and  an edgeedge with one O(2)Nd4 tetrahedra. In the fourth Se site, Se(4) is bonded in a 5-coordinate geometry to one Nd(3), two equivalent Nd(2), and two equivalent Nd(4) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Nd(1), two equivalent Nd(2), and one V(1) atom to form ONd3V tetrahedra that share corners with two equivalent Se(3)Nd5 square pyramids, corners with three equivalent O(1)Nd3V tetrahedra, corners with three equivalent Se(2)Nd5 trigonal bipyramids, edges with two equivalent O(2)Nd4 tetrahedra, and  an edgeedge with one Se(2)Nd5 trigonal bipyramid. In the second O site, O(2) is bonded to one Nd(2), one Nd(4), and two equivalent Nd(1) atoms to form ONd4 tetrahedra that share corners with three equivalent Se(3)Nd5 square pyramids, corners with two equivalent O(2)Nd4 tetrahedra, corners with two equivalent Se(2)Nd5 trigonal bipyramids,  an edgeedge with one Se(3)Nd5 square pyramid, edges with two equivalent O(1)Nd3V tetrahedra, and edges with two equivalent Se(2)Nd5 trigonal bipyramids.