Zn3As2(HO)16 crystallizes in the monoclinic C2/m space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form ZnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra. In the second Zn site, Zn(2) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(5) atoms. As(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form AsO4 tetrahedra that share  a cornercorner with one Zn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. In the second H site, H(2) is bonded in a distorted bent 150 degrees geometry to one O(3) and one O(5) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(5) atom. In the fourth H site, H(4) is bonded in a distorted linear geometry to one O(4) and one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Zn(1) and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Zn(2) and one As(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one As(1) and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Zn(1), one H(1), and one H(4) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Zn(2), one H(2), one H(3), and one H(4) atom.
Zn3As2(HO)16 crystallizes in the monoclinic C2/m space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form ZnO6 octahedra that share corners with two equivalent As(1)O4 tetrahedra. Both Zn(1)-O(1) bond lengths are 2.28 Å. All Zn(1)-O(4) bond lengths are 2.06 Å. In the second Zn site, Zn(2) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(5) atoms. Both Zn(2)-O(2) bond lengths are 2.14 Å. Both Zn(2)-O(5) bond lengths are 1.99 Å. As(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form AsO4 tetrahedra that share  a cornercorner with one Zn(1)O6 octahedra. The corner-sharing octahedral tilt angles are 40°. The As(1)-O(1) bond length is 1.68 Å. The As(1)-O(2) bond length is 1.73 Å. Both As(1)-O(3) bond lengths are 1.76 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. The H(1)-O(4) bond length is 0.98 Å. In the second H site, H(2) is bonded in a distorted bent 150 degrees geometry to one O(3) and one O(5) atom. The H(2)-O(3) bond length is 1.03 Å. The H(2)-O(5) bond length is 1.62 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(5) atom. The H(3)-O(5) bond length is 0.97 Å. In the fourth H site, H(4) is bonded in a distorted linear geometry to one O(4) and one O(5) atom. The H(4)-O(4) bond length is 1.02 Å. The H(4)-O(5) bond length is 1.63 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Zn(1) and one As(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Zn(2) and one As(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one As(1) and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Zn(1), one H(1), and one H(4) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Zn(2), one H(2), one H(3), and one H(4) atom.