Ba2ZnSi2O7 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. Zn(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form ZnO4 tetrahedra that share 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  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Zn(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(1), one Zn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(1) and two equivalent Si(1) atoms.
Ba2ZnSi2O7 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms. The Ba(1)-O(4) bond length is 2.98 Å. There is one shorter (2.85 Å) and one longer (2.87 Å) Ba(1)-O(1) bond length. There is one shorter (2.76 Å) and one longer (2.87 Å) Ba(1)-O(2) bond length. There are a spread of Ba(1)-O(3) bond distances ranging from 2.73-2.90 Å. Zn(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form ZnO4 tetrahedra that share corners with four equivalent Si(1)O4 tetrahedra. Both Zn(1)-O(1) bond lengths are 1.98 Å. Both Zn(1)-O(2) bond lengths are 2.00 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  a cornercorner with one Si(1)O4 tetrahedra and corners with two equivalent Zn(1)O4 tetrahedra. The Si(1)-O(1) bond length is 1.65 Å. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(3) bond length is 1.62 Å. The Si(1)-O(4) bond length is 1.69 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to two equivalent Ba(1), one Zn(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Zn(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to three equivalent Ba(1) and one Si(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Ba(1) and two equivalent Si(1) atoms.