WAs2O7 crystallizes in the monoclinic P2_1/c space group. W(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form distorted WO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with two equivalent W(1)O5 trigonal bipyramids. In the second As site, As(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one W(1) and one As(1) atom. In the second O site, O(7) is bonded in a single-bond geometry to one W(1) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one W(1) and one As(2) atom. In the fourth O site, O(2) is bonded in a bent 120 degrees geometry to one W(1) and one As(1) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one W(1) and one As(2) atom.
WAs2O7 crystallizes in the monoclinic P2_1/c space group. W(1) is bonded to one O(1), one O(2), one O(5), one O(6), and one O(7) atom to form distorted WO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra. The W(1)-O(1) bond length is 1.80 Å. The W(1)-O(2) bond length is 2.08 Å. The W(1)-O(5) bond length is 1.93 Å. The W(1)-O(6) bond length is 1.97 Å. The W(1)-O(7) bond length is 1.74 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(2), one O(3), one O(4), and one O(6) atom to form AsO4 tetrahedra that share corners with two equivalent W(1)O5 trigonal bipyramids. The As(1)-O(2) bond length is 1.73 Å. The As(1)-O(3) bond length is 1.70 Å. The As(1)-O(4) bond length is 1.75 Å. The As(1)-O(6) bond length is 1.72 Å. In the second As site, As(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(4), and one O(5) atom. The As(2)-O(1) bond length is 2.18 Å. The As(2)-O(3) bond length is 2.06 Å. The As(2)-O(4) bond length is 1.92 Å. The As(2)-O(5) bond length is 1.78 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one W(1) and one As(1) atom. In the second O site, O(7) is bonded in a single-bond geometry to one W(1) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one W(1) and one As(2) atom. In the fourth O site, O(2) is bonded in a bent 120 degrees geometry to one W(1) and one As(1) atom. In the fifth O site, O(3) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a bent 120 degrees geometry to one As(1) and one As(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one W(1) and one As(2) atom.