BaZn2Si2O7 crystallizes in the orthorhombic Cmc2_1 space group. Ba(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted BaO5 square pyramids that share corners with four equivalent Zn(1)O4 tetrahedra and corners with six equivalent Si(1)O4 tetrahedra. Zn(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form ZnO4 tetrahedra that share corners with two equivalent Ba(1)O5 square pyramids, corners with two equivalent Zn(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. 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 three equivalent Ba(1)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra, and corners with four equivalent Zn(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ba(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ba(1), one Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one Zn(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Zn(1) and one Si(1) atom.
BaZn2Si2O7 crystallizes in the orthorhombic Cmc2_1 space group. Ba(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted BaO5 square pyramids that share corners with four equivalent Zn(1)O4 tetrahedra and corners with six equivalent Si(1)O4 tetrahedra. The Ba(1)-O(1) bond length is 2.84 Å. Both Ba(1)-O(2) bond lengths are 2.69 Å. Both Ba(1)-O(3) bond lengths are 2.67 Å. Zn(1) is bonded to one O(2), one O(3), and two equivalent O(4) atoms to form ZnO4 tetrahedra that share corners with two equivalent Ba(1)O5 square pyramids, corners with two equivalent Zn(1)O4 tetrahedra, and corners with four equivalent Si(1)O4 tetrahedra. The Zn(1)-O(2) bond length is 1.98 Å. The Zn(1)-O(3) bond length is 1.98 Å. Both Zn(1)-O(4) bond lengths are 2.01 Å. 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 three equivalent Ba(1)O5 square pyramids,  a cornercorner with one Si(1)O4 tetrahedra, and corners with four equivalent Zn(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.70 Å. The Si(1)-O(2) bond length is 1.62 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(4) bond length is 1.66 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ba(1) and two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ba(1), one Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ba(1), one Zn(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Zn(1) and one Si(1) atom.