Na3BSbAsO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. Sb(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(6), and two equivalent O(4) atoms. As(1) is bonded in a tetrahedral geometry to one O(5), one O(6), and two equivalent O(4) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one B(1) atom. In the second O site, O(2) is bonded to one Na(1), two equivalent Na(2), one B(1), and one Sb(1) atom to form distorted ONa3BSb trigonal bipyramids that share corners with two equivalent O(4)Na2SbAs trigonal pyramids,  an edgeedge with one O(3)Na3BSb trigonal bipyramid, edges with two equivalent O(4)Na2SbAs trigonal pyramids, and  a faceface with one O(3)Na3BSb trigonal bipyramid. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), one B(1), and one Sb(1) atom to form distorted ONa3BSb trigonal bipyramids that share corners with six equivalent O(4)Na2SbAs trigonal pyramids,  an edgeedge with one O(2)Na3BSb trigonal bipyramid, and  a faceface with one O(2)Na3BSb trigonal bipyramid. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Sb(1), and one As(1) atom to form distorted ONa2SbAs trigonal pyramids that share  a cornercorner with one O(2)Na3BSb trigonal bipyramid, corners with three equivalent O(3)Na3BSb trigonal bipyramids,  a cornercorner with one O(4)Na2SbAs trigonal pyramid,  an edgeedge with one O(2)Na3BSb trigonal bipyramid, and  an edgeedge with one O(4)Na2SbAs trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na(2) and one As(1) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Na(2), one Sb(1), and one As(1) atom.
Na3BSbAsO7 crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms. The Na(1)-O(2) bond length is 2.65 Å. The Na(1)-O(3) bond length is 2.51 Å. There is one shorter (2.72 Å) and one longer (2.78 Å) Na(1)-O(1) bond length. Both Na(1)-O(4) bond lengths are 2.62 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Na(2)-O(1) bond length is 2.34 Å. The Na(2)-O(2) bond length is 2.56 Å. The Na(2)-O(3) bond length is 2.58 Å. The Na(2)-O(4) bond length is 2.48 Å. The Na(2)-O(5) bond length is 2.40 Å. The Na(2)-O(6) bond length is 2.58 Å. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The B(1)-O(1) bond length is 1.33 Å. The B(1)-O(2) bond length is 1.44 Å. The B(1)-O(3) bond length is 1.42 Å. Sb(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(6), and two equivalent O(4) atoms. The Sb(1)-O(2) bond length is 2.08 Å. The Sb(1)-O(3) bond length is 2.22 Å. The Sb(1)-O(6) bond length is 2.31 Å. Both Sb(1)-O(4) bond lengths are 2.26 Å. As(1) is bonded in a tetrahedral geometry to one O(5), one O(6), and two equivalent O(4) atoms. The As(1)-O(5) bond length is 1.69 Å. The As(1)-O(6) bond length is 1.74 Å. Both As(1)-O(4) bond lengths are 1.75 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Na(2), and one B(1) atom. In the second O site, O(2) is bonded to one Na(1), two equivalent Na(2), one B(1), and one Sb(1) atom to form distorted ONa3BSb trigonal bipyramids that share corners with two equivalent O(4)Na2SbAs trigonal pyramids,  an edgeedge with one O(3)Na3BSb trigonal bipyramid, edges with two equivalent O(4)Na2SbAs trigonal pyramids, and  a faceface with one O(3)Na3BSb trigonal bipyramid. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), one B(1), and one Sb(1) atom to form distorted ONa3BSb trigonal bipyramids that share corners with six equivalent O(4)Na2SbAs trigonal pyramids,  an edgeedge with one O(2)Na3BSb trigonal bipyramid, and  a faceface with one O(2)Na3BSb trigonal bipyramid. In the fourth O site, O(4) is bonded to one Na(1), one Na(2), one Sb(1), and one As(1) atom to form distorted ONa2SbAs trigonal pyramids that share  a cornercorner with one O(2)Na3BSb trigonal bipyramid, corners with three equivalent O(3)Na3BSb trigonal bipyramids,  a cornercorner with one O(4)Na2SbAs trigonal pyramid,  an edgeedge with one O(2)Na3BSb trigonal bipyramid, and  an edgeedge with one O(4)Na2SbAs trigonal pyramid. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Na(2) and one As(1) atom. In the sixth O site, O(6) is bonded in a rectangular see-saw-like geometry to two equivalent Na(2), one Sb(1), and one As(1) atom.