Fe2ZnAs2(HO5)2 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share  a cornercorner with one Zn(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra, and  a faceface with one Zn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-58°. Zn(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra, and faces with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 58°. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-55°. H(1) is bonded in a single-bond geometry to one O(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(1), one Zn(1), and one As(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Fe(1), one Zn(1), and one As(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Fe(1), one Zn(1), and one H(1) atom.
Fe2ZnAs2(HO5)2 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share  a cornercorner with one Zn(1)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra, and  a faceface with one Zn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 44-58°. The Fe(1)-O(1) bond length is 2.10 Å. The Fe(1)-O(2) bond length is 1.97 Å. The Fe(1)-O(3) bond length is 1.92 Å. The Fe(1)-O(4) bond length is 2.07 Å. There is one shorter (2.06 Å) and one longer (2.18 Å) Fe(1)-O(5) bond length. Zn(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted ZnO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent As(1)O4 tetrahedra, and faces with two equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles are 58°. Both Zn(1)-O(1) bond lengths are 2.06 Å. Both Zn(1)-O(4) bond lengths are 2.16 Å. Both Zn(1)-O(5) bond lengths are 2.17 Å. As(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AsO4 tetrahedra that share corners with two equivalent Zn(1)O6 octahedra and corners with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-55°. The As(1)-O(1) bond length is 1.72 Å. The As(1)-O(2) bond length is 1.72 Å. The As(1)-O(3) bond length is 1.70 Å. The As(1)-O(4) bond length is 1.73 Å. H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.98 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Fe(1), one Zn(1), and one As(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Fe(1) and one As(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Fe(1) and one As(1) atom. In the fourth O site, O(4) is bonded in a distorted T-shaped geometry to one Fe(1), one Zn(1), and one As(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Fe(1), one Zn(1), and one H(1) atom.