Zn3As3H2(CO8)2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(13), one O(14), one O(15), one O(16), one O(2), and one O(6) atom to form ZnO6 octahedra that share  a cornercorner with one As(1)O4 tetrahedra and  a cornercorner with one As(2)O4 tetrahedra. The Zn(1)-O(13) bond length is 2.12 Å. The Zn(1)-O(14) bond length is 2.16 Å. The Zn(1)-O(15) bond length is 2.15 Å. The Zn(1)-O(16) bond length is 2.20 Å. The Zn(1)-O(2) bond length is 2.04 Å. The Zn(1)-O(6) bond length is 2.01 Å. In the second Zn site, Zn(2) is bonded to one O(1), one O(10), one O(12), and one O(5) atom to form ZnO4 tetrahedra that share  a cornercorner with one As(1)O4 tetrahedra,  a cornercorner with one As(2)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. The Zn(2)-O(1) bond length is 1.95 Å. The Zn(2)-O(10) bond length is 1.98 Å. The Zn(2)-O(12) bond length is 1.93 Å. The Zn(2)-O(5) bond length is 1.94 Å. In the third Zn site, Zn(3) is bonded to one O(11), one O(3), one O(7), and one O(9) atom to form ZnO4 tetrahedra that share  a cornercorner with one As(1)O4 tetrahedra,  a cornercorner with one As(2)O4 tetrahedra, and corners with two equivalent As(3)O4 tetrahedra. The Zn(3)-O(11) bond length is 1.93 Å. The Zn(3)-O(3) bond length is 1.98 Å. The Zn(3)-O(7) bond length is 1.97 Å. The Zn(3)-O(9) bond length is 1.93 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(13) and one O(16) atom. The C(1)-O(13) bond length is 1.27 Å. The C(1)-O(16) bond length is 1.25 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(14) and one O(15) atom. The C(2)-O(14) bond length is 1.25 Å. The C(2)-O(15) bond length is 1.27 Å. There are three inequivalent As sites. In the first As site, 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  a cornercorner with one Zn(1)O6 octahedra,  a cornercorner with one Zn(2)O4 tetrahedra, and  a cornercorner with one Zn(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. The As(1)-O(1) bond length is 1.66 Å. The As(1)-O(2) bond length is 1.66 Å. The As(1)-O(3) bond length is 1.68 Å. The As(1)-O(4) bond length is 1.74 Å. In the second As site, As(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form AsO4 tetrahedra that share  a cornercorner with one Zn(1)O6 octahedra,  a cornercorner with one Zn(2)O4 tetrahedra, and  a cornercorner with one Zn(3)O4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. The As(2)-O(5) bond length is 1.66 Å. The As(2)-O(6) bond length is 1.65 Å. The As(2)-O(7) bond length is 1.70 Å. The As(2)-O(8) bond length is 1.72 Å. In the third As site, As(3) is bonded to one O(10), one O(11), one O(12), and one O(9) atom to form AsO4 tetrahedra that share corners with two equivalent Zn(2)O4 tetrahedra and corners with two equivalent Zn(3)O4 tetrahedra. The As(3)-O(10) bond length is 1.69 Å. The As(3)-O(11) bond length is 1.68 Å. The As(3)-O(12) bond length is 1.68 Å. The As(3)-O(9) bond length is 1.67 Å. There are two 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 0.82 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(8) atom. The H(2)-O(8) bond length is 0.82 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Zn(2) and one As(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Zn(1) and one As(1) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(3) and one As(1) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one As(1) and one H(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Zn(2) and one As(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Zn(1) and one As(2) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Zn(3) and one As(2) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one As(2) and one H(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Zn(3) and one As(3) atom. In the tenth O site, O(10) is bonded in a bent 120 degrees geometry to one Zn(2) and one As(3) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one Zn(3) and one As(3) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one Zn(2) and one As(3) atom. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(1) atom. In the fourteenth O site, O(14) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(2) atom. In the fifteenth O site, O(15) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(2) atom. In the sixteenth O site, O(16) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(1) atom. Linkers: 3 [O]C(=O)C([O])=O. Metal clusters: 12 [Zn]. The MOF has largest included sphere 4.75 A, density 2.21 g/cm3, surface area 2569.94 m2/g, accessible volume 0.18 cm3/g