CoZnSiO5 crystallizes in the triclinic P-1 space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form CoO6 octahedra that share corners with two equivalent Co(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with four equivalent Zn(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 42°. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form CoO6 octahedra that share corners with two equivalent Co(1)O6 octahedra, corners with two equivalent Zn(1)O6 pentagonal pyramids, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Zn(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 42°. Zn(1) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form distorted ZnO6 pentagonal pyramids that share  a cornercorner with one Co(2)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra, edges with two equivalent Co(1)O6 octahedra,  an edgeedge with one Zn(1)O6 pentagonal pyramid, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Co(1)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with three equivalent Zn(1)O6 pentagonal pyramids, and  an edgeedge with one Zn(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 30-52°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Co(2), one Zn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), two equivalent Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Co(1), one Zn(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(2), one Zn(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one Zn(1) atom.
CoZnSiO5 crystallizes in the triclinic P-1 space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form CoO6 octahedra that share corners with two equivalent Co(2)O6 octahedra, corners with four equivalent Si(1)O4 tetrahedra, and edges with four equivalent Zn(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 42°. Both Co(1)-O(2) bond lengths are 2.07 Å. Both Co(1)-O(3) bond lengths are 1.93 Å. Both Co(1)-O(5) bond lengths are 1.84 Å. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form CoO6 octahedra that share corners with two equivalent Co(1)O6 octahedra, corners with two equivalent Zn(1)O6 pentagonal pyramids, corners with four equivalent Si(1)O4 tetrahedra, and edges with two equivalent Zn(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 42°. Both Co(2)-O(1) bond lengths are 1.98 Å. Both Co(2)-O(4) bond lengths are 1.95 Å. Both Co(2)-O(5) bond lengths are 1.82 Å. Zn(1) is bonded to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms to form distorted ZnO6 pentagonal pyramids that share  a cornercorner with one Co(2)O6 octahedra, corners with three equivalent Si(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra, edges with two equivalent Co(1)O6 octahedra,  an edgeedge with one Zn(1)O6 pentagonal pyramid, and  an edgeedge with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. The Zn(1)-O(1) bond length is 2.18 Å. The Zn(1)-O(3) bond length is 2.11 Å. The Zn(1)-O(4) bond length is 2.07 Å. The Zn(1)-O(5) bond length is 1.98 Å. There is one shorter (2.21 Å) and one longer (2.45 Å) Zn(1)-O(2) bond length. Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Co(1)O6 octahedra, corners with two equivalent Co(2)O6 octahedra, corners with three equivalent Zn(1)O6 pentagonal pyramids, and  an edgeedge with one Zn(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles range from 30-52°. The Si(1)-O(1) bond length is 1.64 Å. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(3) bond length is 1.60 Å. The Si(1)-O(4) bond length is 1.70 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Co(2), one Zn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Co(1), two equivalent Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Co(1), one Zn(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(2), one Zn(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one Zn(1) atom.