Cu3(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form CuO5 trigonal bipyramids that share corners with two equivalent As(2)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra,  a cornercorner with one Cu(2)O5 trigonal bipyramid,  a cornercorner with one Cu(3)O5 trigonal bipyramid, and  an edgeedge with one Cu(3)O5 trigonal bipyramid. In the second Cu site, Cu(2) is bonded to one O(1), one O(4), one O(5), and two equivalent O(6) atoms to form distorted CuO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid,  an edgeedge with one Cu(2)O5 trigonal bipyramid, and  an edgeedge with one Cu(3)O5 trigonal bipyramid. In the third Cu site, Cu(3) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(8) atom to form CuO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid,  an edgeedge with one Cu(1)O5 trigonal bipyramid, and  an edgeedge with one Cu(2)O5 trigonal bipyramid. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(2)O5 trigonal bipyramids, corners with two equivalent Cu(3)O5 trigonal bipyramids, and corners with three equivalent Cu(1)O5 trigonal bipyramids. In the second As site, As(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(1)O5 trigonal bipyramids, corners with three equivalent Cu(2)O5 trigonal bipyramids, and corners with three equivalent Cu(3)O5 trigonal bipyramids. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to one Cu(2), one Cu(3), and one As(2) atom. In the second O site, O(5) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one As(1) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Cu(2) and one As(2) atom. In the fourth O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(1) atom. In the fifth O site, O(8) is bonded in a trigonal planar geometry to one Cu(1), one Cu(3), and one As(2) atom. In the sixth O site, O(1) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one As(1) atom. In the seventh O site, O(2) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(3), and one As(2) atom. In the eighth O site, O(3) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(3), and one As(1) atom.
Cu3(AsO4)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form CuO5 trigonal bipyramids that share corners with two equivalent As(2)O4 tetrahedra, corners with three equivalent As(1)O4 tetrahedra,  a cornercorner with one Cu(2)O5 trigonal bipyramid,  a cornercorner with one Cu(3)O5 trigonal bipyramid, and  an edgeedge with one Cu(3)O5 trigonal bipyramid. The Cu(1)-O(2) bond length is 1.97 Å. The Cu(1)-O(3) bond length is 2.03 Å. The Cu(1)-O(5) bond length is 1.98 Å. The Cu(1)-O(7) bond length is 1.90 Å. The Cu(1)-O(8) bond length is 2.10 Å. In the second Cu site, Cu(2) is bonded to one O(1), one O(4), one O(5), and two equivalent O(6) atoms to form distorted CuO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid,  an edgeedge with one Cu(2)O5 trigonal bipyramid, and  an edgeedge with one Cu(3)O5 trigonal bipyramid. The Cu(2)-O(1) bond length is 2.03 Å. The Cu(2)-O(4) bond length is 1.91 Å. The Cu(2)-O(5) bond length is 2.00 Å. There is one shorter (1.90 Å) and one longer (2.33 Å) Cu(2)-O(6) bond length. In the third Cu site, Cu(3) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(8) atom to form CuO5 trigonal bipyramids that share corners with two equivalent As(1)O4 tetrahedra, corners with three equivalent As(2)O4 tetrahedra,  a cornercorner with one Cu(1)O5 trigonal bipyramid,  an edgeedge with one Cu(1)O5 trigonal bipyramid, and  an edgeedge with one Cu(2)O5 trigonal bipyramid. The Cu(3)-O(1) bond length is 1.96 Å. The Cu(3)-O(2) bond length is 2.05 Å. The Cu(3)-O(3) bond length is 1.93 Å. The Cu(3)-O(4) bond length is 2.15 Å. The Cu(3)-O(8) bond length is 1.93 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded to one O(1), one O(3), one O(5), and one O(7) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(2)O5 trigonal bipyramids, corners with two equivalent Cu(3)O5 trigonal bipyramids, and corners with three equivalent Cu(1)O5 trigonal bipyramids. The As(1)-O(1) bond length is 1.71 Å. The As(1)-O(3) bond length is 1.71 Å. The As(1)-O(5) bond length is 1.72 Å. The As(1)-O(7) bond length is 1.68 Å. In the second As site, As(2) is bonded to one O(2), one O(4), one O(6), and one O(8) atom to form AsO4 tetrahedra that share corners with two equivalent Cu(1)O5 trigonal bipyramids, corners with three equivalent Cu(2)O5 trigonal bipyramids, and corners with three equivalent Cu(3)O5 trigonal bipyramids. The As(2)-O(2) bond length is 1.72 Å. The As(2)-O(4) bond length is 1.70 Å. The As(2)-O(6) 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(4) is bonded in a distorted trigonal planar geometry to one Cu(2), one Cu(3), and one As(2) atom. In the second O site, O(5) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one As(1) atom. In the third O site, O(6) is bonded in a 3-coordinate geometry to two equivalent Cu(2) and one As(2) atom. In the fourth O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(1) and one As(1) atom. In the fifth O site, O(8) is bonded in a trigonal planar geometry to one Cu(1), one Cu(3), and one As(2) atom. In the sixth O site, O(1) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one As(1) atom. In the seventh O site, O(2) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(3), and one As(2) atom. In the eighth O site, O(3) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(3), and one As(1) atom.