Na2Sb4O7 crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), and two equivalent O(2) atoms. In the second Sb site, Sb(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(4) is bonded to two equivalent Na(1) and two equivalent Sb(2) atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 trigonal pyramids. In the second O site, O(1) is bonded to two equivalent Na(1), one Sb(1), and one Sb(2) atom to form a mixture of corner and edge-sharing ONa2Sb2 tetrahedra. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Sb(2) and two equivalent Sb(1) atoms. In the fourth O site, O(3) is bonded to two equivalent Na(1) and two equivalent Sb(1) atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 trigonal pyramids.
Na2Sb4O7 crystallizes in the monoclinic C2/c space group. Na(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(4) atoms. The Na(1)-O(3) bond length is 2.36 Å. There is one shorter (2.27 Å) and one longer (2.40 Å) Na(1)-O(1) bond length. There is one shorter (2.33 Å) and one longer (2.46 Å) Na(1)-O(4) bond length. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(3), and two equivalent O(2) atoms. The Sb(1)-O(1) bond length is 2.10 Å. The Sb(1)-O(3) bond length is 1.99 Å. There is one shorter (2.00 Å) and one longer (2.17 Å) Sb(1)-O(2) bond length. In the second Sb site, Sb(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), and two equivalent O(4) atoms. The Sb(2)-O(1) bond length is 1.96 Å. The Sb(2)-O(2) bond length is 2.32 Å. There is one shorter (1.97 Å) and one longer (2.14 Å) Sb(2)-O(4) bond length. There are four inequivalent O sites. In the first O site, O(4) is bonded to two equivalent Na(1) and two equivalent Sb(2) atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 trigonal pyramids. In the second O site, O(1) is bonded to two equivalent Na(1), one Sb(1), and one Sb(2) atom to form a mixture of corner and edge-sharing ONa2Sb2 tetrahedra. In the third O site, O(2) is bonded in a 3-coordinate geometry to one Sb(2) and two equivalent Sb(1) atoms. In the fourth O site, O(3) is bonded to two equivalent Na(1) and two equivalent Sb(1) atoms to form a mixture of distorted corner and edge-sharing ONa2Sb2 trigonal pyramids.