Na2Cu3Bi2As2O13 crystallizes in the monoclinic C2 space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), and two equivalent O(3) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(5), and one O(6) atom. Bi(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(5), and two equivalent O(6) atoms. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share  a cornercorner with one Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles are 71°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Cu(1), one Bi(1), and one As(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Cu(2), one Bi(1), and one As(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Cu(2), and one As(1) atom. In the fifth O site, O(5) is bonded to one Cu(1), one Cu(2), and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OCu2Bi2 tetrahedra. In the sixth O site, O(6) is bonded to one Cu(1), one Cu(2), and two equivalent Bi(1) atoms to form a mixture of edge and corner-sharing OCu2Bi2 tetrahedra. In the seventh O site, O(7) is bonded in an L-shaped geometry to two equivalent Na(1) atoms.
Na2Cu3Bi2As2O13 crystallizes in the monoclinic C2 space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(4), one O(7), and two equivalent O(3) atoms. The Na(1)-O(2) bond length is 2.44 Å. The Na(1)-O(4) bond length is 2.48 Å. The Na(1)-O(7) bond length is 2.53 Å. There is one shorter (2.29 Å) and one longer (2.65 Å) Na(1)-O(3) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms to form distorted CuO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra. Both Cu(1)-O(1) bond lengths are 2.54 Å. Both Cu(1)-O(5) bond lengths are 1.96 Å. Both Cu(1)-O(6) bond lengths are 1.96 Å. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(5), and one O(6) atom. The Cu(2)-O(2) bond length is 1.98 Å. The Cu(2)-O(4) bond length is 1.92 Å. The Cu(2)-O(5) bond length is 1.95 Å. The Cu(2)-O(6) bond length is 1.94 Å. Bi(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), two equivalent O(5), and two equivalent O(6) atoms. The Bi(1)-O(1) bond length is 2.76 Å. The Bi(1)-O(2) bond length is 2.71 Å. There is one shorter (2.25 Å) and one longer (2.52 Å) Bi(1)-O(5) bond length. There is one shorter (2.26 Å) and one longer (2.29 Å) Bi(1)-O(6) bond length. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share  a cornercorner with one Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles are 71°. The As(1)-O(1) bond length is 1.75 Å. The As(1)-O(2) bond length is 1.78 Å. The As(1)-O(3) bond length is 1.69 Å. The As(1)-O(4) bond length is 1.75 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Cu(1), one Bi(1), and one As(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Cu(2), one Bi(1), and one As(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Na(1), one Cu(2), and one As(1) atom. In the fifth O site, O(5) is bonded to one Cu(1), one Cu(2), and two equivalent Bi(1) atoms to form a mixture of distorted edge and corner-sharing OCu2Bi2 tetrahedra. In the sixth O site, O(6) is bonded to one Cu(1), one Cu(2), and two equivalent Bi(1) atoms to form a mixture of edge and corner-sharing OCu2Bi2 tetrahedra. In the seventh O site, O(7) is bonded in an L-shaped geometry to two equivalent Na(1) atoms.