SrZrSi2O7 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form ZrO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-59°. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-53°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the third O site, O(7) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Zr(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one Zr(1) and one Si(2) atom.
SrZrSi2O7 crystallizes in the monoclinic P2_1/c space group. Sr(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(5), one O(6), one O(7), and two equivalent O(1) atoms. The Sr(1)-O(2) bond length is 2.68 Å. The Sr(1)-O(3) bond length is 2.61 Å. The Sr(1)-O(5) bond length is 2.62 Å. The Sr(1)-O(6) bond length is 2.63 Å. The Sr(1)-O(7) bond length is 2.57 Å. There is one shorter (2.61 Å) and one longer (3.05 Å) Sr(1)-O(1) bond length. Zr(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form ZrO6 octahedra that share corners with three equivalent Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. The Zr(1)-O(1) bond length is 2.23 Å. The Zr(1)-O(2) bond length is 2.16 Å. The Zr(1)-O(3) bond length is 2.09 Å. The Zr(1)-O(4) bond length is 2.02 Å. The Zr(1)-O(6) bond length is 2.13 Å. The Zr(1)-O(7) bond length is 2.13 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 29-59°. The Si(1)-O(1) bond length is 1.65 Å. The Si(1)-O(2) bond length is 1.63 Å. The Si(1)-O(3) bond length is 1.63 Å. The Si(1)-O(5) bond length is 1.68 Å. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form SiO4 tetrahedra that share corners with three equivalent Zr(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-53°. The Si(2)-O(4) bond length is 1.62 Å. The Si(2)-O(5) bond length is 1.67 Å. The Si(2)-O(6) bond length is 1.63 Å. The Si(2)-O(7) bond length is 1.64 Å. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Sr(1), one Si(1), and one Si(2) atom. In the second O site, O(6) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the third O site, O(7) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(2) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Zr(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a distorted trigonal planar geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the sixth O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Zr(1), and one Si(1) atom. In the seventh O site, O(4) is bonded in a distorted linear geometry to one Zr(1) and one Si(2) atom.