CuPbAs2O7 crystallizes in the monoclinic P2_1/c space group. Cu(1) is bonded to one O(1), one O(3), one O(4), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent As(2)O4 tetrahedra and corners with three equivalent As(1)O4 tetrahedra. Pb(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(6), one O(7), and two equivalent O(2) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one As(2)O4 tetrahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. In the second As site, As(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form AsO4 tetrahedra that share  a cornercorner with one As(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the second O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cu(1), one Pb(1), and one As(1) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Cu(1), one Pb(1), and one As(1) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one Cu(1), one Pb(1), and one As(2) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Pb(1) and one As(2) atom. In the sixth O site, O(3) is bonded in a 2-coordinate geometry to one Cu(1), one Pb(1), and one As(2) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(1) atom.
CuPbAs2O7 crystallizes in the monoclinic P2_1/c space group. Cu(1) is bonded to one O(1), one O(3), one O(4), one O(6), and one O(7) atom to form distorted CuO5 trigonal bipyramids that share corners with two equivalent As(2)O4 tetrahedra and corners with three equivalent As(1)O4 tetrahedra. The Cu(1)-O(1) bond length is 1.97 Å. The Cu(1)-O(3) bond length is 2.03 Å. The Cu(1)-O(4) bond length is 1.98 Å. The Cu(1)-O(6) bond length is 1.98 Å. The Cu(1)-O(7) bond length is 2.36 Å. Pb(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(6), one O(7), and two equivalent O(2) atoms. The Pb(1)-O(1) bond length is 2.63 Å. The Pb(1)-O(3) bond length is 2.65 Å. The Pb(1)-O(6) bond length is 2.74 Å. The Pb(1)-O(7) bond length is 2.56 Å. There is one shorter (2.52 Å) and one longer (2.63 Å) Pb(1)-O(2) bond length. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form AsO4 tetrahedra that share  a cornercorner with one As(2)O4 tetrahedra and corners with three equivalent Cu(1)O5 trigonal bipyramids. The As(1)-O(4) bond length is 1.73 Å. The As(1)-O(5) bond length is 1.81 Å. The As(1)-O(6) bond length is 1.73 Å. The As(1)-O(7) bond length is 1.69 Å. In the second As site, As(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form AsO4 tetrahedra that share  a cornercorner with one As(1)O4 tetrahedra and corners with two equivalent Cu(1)O5 trigonal bipyramids. The As(2)-O(1) bond length is 1.71 Å. The As(2)-O(2) bond length is 1.70 Å. The As(2)-O(3) bond length is 1.73 Å. The As(2)-O(5) bond length is 1.77 Å. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the second O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Cu(1), one Pb(1), and one As(1) atom. In the third O site, O(7) is bonded in a 3-coordinate geometry to one Cu(1), one Pb(1), and one As(1) atom. In the fourth O site, O(1) is bonded in a 3-coordinate geometry to one Cu(1), one Pb(1), and one As(2) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Pb(1) and one As(2) atom. In the sixth O site, O(3) is bonded in a 2-coordinate geometry to one Cu(1), one Pb(1), and one As(2) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(1) atom.