Na(AsO3)2 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form corner-sharing AsO4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-59°. In the second As site, As(2) is bonded to one O(2), one O(3), one O(4), one O(6), and two equivalent O(1) atoms to form AsO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra and  an edgeedge with one As(2)O6 octahedra. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the second O site, O(1) is bonded in a distorted T-shaped geometry to one Na(1) and two equivalent As(2) atoms. In the third O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Na(1) and one As(2) atom. In the fourth O site, O(3) is bonded in a trigonal planar geometry to one Na(1), one As(1), and one As(2) atom. In the fifth O site, O(4) is bonded in a trigonal planar geometry to one Na(1), one As(1), and one As(2) atom. In the sixth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one As(1) atom.
Na(AsO3)2 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 7-coordinate geometry to one O(1), one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms. The Na(1)-O(1) bond length is 2.50 Å. The Na(1)-O(3) bond length is 2.45 Å. The Na(1)-O(4) bond length is 2.35 Å. There is one shorter (2.73 Å) and one longer (2.75 Å) Na(1)-O(2) bond length. There is one shorter (2.44 Å) and one longer (2.53 Å) Na(1)-O(5) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form corner-sharing AsO4 tetrahedra. The corner-sharing octahedral tilt angles range from 58-59°. The As(1)-O(3) bond length is 1.76 Å. The As(1)-O(4) bond length is 1.73 Å. The As(1)-O(5) bond length is 1.71 Å. The As(1)-O(6) bond length is 1.74 Å. In the second As site, As(2) is bonded to one O(2), one O(3), one O(4), one O(6), and two equivalent O(1) atoms to form AsO6 octahedra that share corners with three equivalent As(1)O4 tetrahedra and  an edgeedge with one As(2)O6 octahedra. The As(2)-O(2) bond length is 1.78 Å. The As(2)-O(3) bond length is 1.91 Å. The As(2)-O(4) bond length is 1.97 Å. The As(2)-O(6) bond length is 1.91 Å. Both As(2)-O(1) bond lengths are 1.85 Å. There are six inequivalent O sites. In the first O site, O(6) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the second O site, O(1) is bonded in a distorted T-shaped geometry to one Na(1) and two equivalent As(2) atoms. In the third O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Na(1) and one As(2) atom. In the fourth O site, O(3) is bonded in a trigonal planar geometry to one Na(1), one As(1), and one As(2) atom. In the fifth O site, O(4) is bonded in a trigonal planar geometry to one Na(1), one As(1), and one As(2) atom. In the sixth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent Na(1) and one As(1) atom.