Na2Cu4P2O9Cl crystallizes in the orthorhombic Cmcm space group. Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(4), two equivalent O(1), and one Cl(1) atom to form distorted CuClO4 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, edges with two equivalent Cu(2)O6 octahedra, and  an edgeedge with one Cu(1)ClO4 trigonal bipyramid. In the second Cu site, Cu(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(2)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with four equivalent Cu(1)ClO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 59°. In the third Cu site, Cu(3) is bonded in a distorted T-shaped geometry to two equivalent O(3) and one Cl(1) atom. P(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Cu(2)O6 octahedra and corners with three equivalent Cu(1)ClO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 46°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Cu(1), one Cu(2), and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Cu(1), and one P(1) atom. In the third O site, O(3) is bonded to two equivalent Na(1), one Cu(3), and one P(1) atom to form distorted corner-sharing ONa2CuP tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Cu(1) and two equivalent Cu(2) atoms to form corner-sharing OCu4 tetrahedra. Cl(1) is bonded in a 3-coordinate geometry to one Cu(3) and two equivalent Cu(1) atoms.
Na2Cu4P2O9Cl crystallizes in the orthorhombic Cmcm space group. Na(1) is bonded in a 4-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Na(1)-O(1) bond lengths are 2.88 Å. Both Na(1)-O(2) bond lengths are 2.51 Å. Both Na(1)-O(3) bond lengths are 2.38 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(4), two equivalent O(1), and one Cl(1) atom to form distorted CuClO4 trigonal bipyramids that share corners with three equivalent P(1)O4 tetrahedra, edges with two equivalent Cu(2)O6 octahedra, and  an edgeedge with one Cu(1)ClO4 trigonal bipyramid. The Cu(1)-O(2) bond length is 1.94 Å. The Cu(1)-O(4) bond length is 1.94 Å. Both Cu(1)-O(1) bond lengths are 2.10 Å. The Cu(1)-Cl(1) bond length is 2.61 Å. In the second Cu site, Cu(2) is bonded to two equivalent O(4) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share corners with two equivalent Cu(2)O6 octahedra, corners with four equivalent P(1)O4 tetrahedra, and edges with four equivalent Cu(1)ClO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 59°. Both Cu(2)-O(4) bond lengths are 1.87 Å. All Cu(2)-O(1) bond lengths are 2.25 Å. In the third Cu site, Cu(3) is bonded in a distorted T-shaped geometry to two equivalent O(3) and one Cl(1) atom. Both Cu(3)-O(3) bond lengths are 1.96 Å. The Cu(3)-Cl(1) bond length is 2.34 Å. P(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with two equivalent Cu(2)O6 octahedra and corners with three equivalent Cu(1)ClO4 trigonal bipyramids. The corner-sharing octahedral tilt angles are 46°. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.57 Å. Both P(1)-O(1) bond lengths are 1.55 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Cu(1), one Cu(2), and one P(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Cu(1), and one P(1) atom. In the third O site, O(3) is bonded to two equivalent Na(1), one Cu(3), and one P(1) atom to form distorted corner-sharing ONa2CuP tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Cu(1) and two equivalent Cu(2) atoms to form corner-sharing OCu4 tetrahedra. Cl(1) is bonded in a 3-coordinate geometry to one Cu(3) and two equivalent Cu(1) atoms.