Na5Cu3(AsO4)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to two equivalent O(2), two equivalent O(5), and two equivalent O(8) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(3), one O(6), one O(8), and two equivalent O(4) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form CuO5 square pyramids that share corners with two equivalent As(1)O4 tetrahedra and corners with three equivalent As(2)O4 tetrahedra. There are two inequivalent As sites. In the first As site, 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 corners with two equivalent Cu(2)O5 square pyramids. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share corners with three equivalent Cu(2)O5 square pyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Na(1), one Cu(2), and one As(1) atom. In the third O site, O(3) is bonded to one Na(2), one Na(3), one Cu(1), and one As(1) atom to form distorted corner-sharing ONa2CuAs trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(3), and one As(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Cu(2), and one As(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Cu(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(2), one Cu(2), and one As(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Na(3), and one As(2) atom.
Na5Cu3(AsO4)4 crystallizes in the triclinic P-1 space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to two equivalent O(2), two equivalent O(5), and two equivalent O(8) atoms. Both Na(1)-O(2) bond lengths are 2.39 Å. Both Na(1)-O(5) bond lengths are 2.79 Å. Both Na(1)-O(8) bond lengths are 2.60 Å. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(3), one O(4), one O(5), one O(6), and one O(7) atom. The Na(2)-O(3) bond length is 2.44 Å. The Na(2)-O(4) bond length is 2.50 Å. The Na(2)-O(5) bond length is 2.37 Å. The Na(2)-O(6) bond length is 2.48 Å. The Na(2)-O(7) bond length is 2.30 Å. In the third Na site, Na(3) is bonded in a 5-coordinate geometry to one O(3), one O(6), one O(8), and two equivalent O(4) atoms. The Na(3)-O(3) bond length is 2.41 Å. The Na(3)-O(6) bond length is 2.52 Å. The Na(3)-O(8) bond length is 2.26 Å. There is one shorter (2.36 Å) and one longer (2.41 Å) Na(3)-O(4) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both Cu(1)-O(1) bond lengths are 2.06 Å. Both Cu(1)-O(3) bond lengths are 1.95 Å. In the second Cu site, Cu(2) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form CuO5 square pyramids that share corners with two equivalent As(1)O4 tetrahedra and corners with three equivalent As(2)O4 tetrahedra. The Cu(2)-O(1) bond length is 1.98 Å. The Cu(2)-O(2) bond length is 1.93 Å. The Cu(2)-O(5) bond length is 1.90 Å. The Cu(2)-O(6) bond length is 1.90 Å. The Cu(2)-O(7) bond length is 2.29 Å. There are two inequivalent As sites. In the first As site, 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 corners with two equivalent Cu(2)O5 square pyramids. The As(1)-O(1) bond length is 1.79 Å. The As(1)-O(2) bond length is 1.72 Å. The As(1)-O(3) bond length is 1.74 Å. The As(1)-O(4) bond length is 1.70 Å. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share corners with three equivalent Cu(2)O5 square pyramids. The As(2)-O(5) bond length is 1.77 Å. The As(2)-O(6) bond length is 1.79 Å. The As(2)-O(7) bond length is 1.69 Å. The As(2)-O(8) bond length is 1.70 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one As(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Na(1), one Cu(2), and one As(1) atom. In the third O site, O(3) is bonded to one Na(2), one Na(3), one Cu(1), and one As(1) atom to form distorted corner-sharing ONa2CuAs trigonal pyramids. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), two equivalent Na(3), and one As(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Cu(2), and one As(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Cu(2), and one As(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Na(2), one Cu(2), and one As(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Na(1), one Na(3), and one As(2) atom.