Si2N2O is beta indium sulfide-derived structured and crystallizes in the trigonal P-3m1 space group. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(2), one N(4), two equivalent N(1), and two equivalent O(2) atoms to form SiN4O2 octahedra that share  a cornercorner with one Si(5)N4 tetrahedra, corners with three equivalent Si(6)N4 tetrahedra,  an edgeedge with one Si(4)N3O3 octahedra,  an edgeedge with one Si(3)N6 octahedra, and edges with four equivalent Si(1)N4O2 octahedra. In the second Si site, Si(2) is bonded to four equivalent N(3) and two equivalent O(1) atoms to form SiN4O2 octahedra that share corners with four equivalent Si(5)N4 tetrahedra, edges with two equivalent Si(4)N3O3 octahedra, and edges with four equivalent Si(2)N4O2 octahedra. In the third Si site, Si(3) is bonded to six equivalent N(1) atoms to form SiN6 octahedra that share corners with six equivalent Si(6)N4 tetrahedra and edges with six equivalent Si(1)N4O2 octahedra. In the fourth Si site, Si(4) is bonded to three equivalent N(3) and three equivalent O(2) atoms to form SiN3O3 octahedra that share corners with three equivalent Si(5)N4 tetrahedra, edges with three equivalent Si(1)N4O2 octahedra, and edges with three equivalent Si(2)N4O2 octahedra. In the fifth Si site, Si(5) is bonded to one N(4) and three equivalent N(3) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(4)N3O3 octahedra, corners with three equivalent Si(1)N4O2 octahedra, and corners with six equivalent Si(2)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. In the sixth Si site, Si(6) is bonded to one N(2) and three equivalent N(1) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(3)N6 octahedra and corners with nine equivalent Si(1)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Si(3), one Si(6), and two equivalent Si(1) atoms to form a mixture of distorted edge and corner-sharing NSi4 trigonal pyramids. In the second N site, N(2) is bonded in a rectangular see-saw-like geometry to one Si(6) and three equivalent Si(1) atoms. In the third N site, N(3) is bonded in a distorted rectangular see-saw-like geometry to one Si(4), one Si(5), and two equivalent Si(2) atoms. In the fourth N site, N(4) is bonded to one Si(5) and three equivalent Si(1) atoms to form distorted edge-sharing NSi4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Si(4) and two equivalent Si(1) atoms.
Si2N2O is beta indium sulfide-derived structured and crystallizes in the trigonal P-3m1 space group. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one N(2), one N(4), two equivalent N(1), and two equivalent O(2) atoms to form SiN4O2 octahedra that share  a cornercorner with one Si(5)N4 tetrahedra, corners with three equivalent Si(6)N4 tetrahedra,  an edgeedge with one Si(4)N3O3 octahedra,  an edgeedge with one Si(3)N6 octahedra, and edges with four equivalent Si(1)N4O2 octahedra. The Si(1)-N(2) bond length is 1.89 Å. The Si(1)-N(4) bond length is 1.90 Å. Both Si(1)-N(1) bond lengths are 1.87 Å. Both Si(1)-O(2) bond lengths are 1.81 Å. In the second Si site, Si(2) is bonded to four equivalent N(3) and two equivalent O(1) atoms to form SiN4O2 octahedra that share corners with four equivalent Si(5)N4 tetrahedra, edges with two equivalent Si(4)N3O3 octahedra, and edges with four equivalent Si(2)N4O2 octahedra. All Si(2)-N(3) bond lengths are 1.91 Å. Both Si(2)-O(1) bond lengths are 1.80 Å. In the third Si site, Si(3) is bonded to six equivalent N(1) atoms to form SiN6 octahedra that share corners with six equivalent Si(6)N4 tetrahedra and edges with six equivalent Si(1)N4O2 octahedra. All Si(3)-N(1) bond lengths are 1.90 Å. In the fourth Si site, Si(4) is bonded to three equivalent N(3) and three equivalent O(2) atoms to form SiN3O3 octahedra that share corners with three equivalent Si(5)N4 tetrahedra, edges with three equivalent Si(1)N4O2 octahedra, and edges with three equivalent Si(2)N4O2 octahedra. All Si(4)-N(3) bond lengths are 1.89 Å. All Si(4)-O(2) bond lengths are 1.82 Å. In the fifth Si site, Si(5) is bonded to one N(4) and three equivalent N(3) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(4)N3O3 octahedra, corners with three equivalent Si(1)N4O2 octahedra, and corners with six equivalent Si(2)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 57-58°. The Si(5)-N(4) bond length is 1.76 Å. All Si(5)-N(3) bond lengths are 1.78 Å. In the sixth Si site, Si(6) is bonded to one N(2) and three equivalent N(1) atoms to form SiN4 tetrahedra that share corners with three equivalent Si(3)N6 octahedra and corners with nine equivalent Si(1)N4O2 octahedra. The corner-sharing octahedral tilt angles range from 56-58°. The Si(6)-N(2) bond length is 1.77 Å. All Si(6)-N(1) bond lengths are 1.77 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded to one Si(3), one Si(6), and two equivalent Si(1) atoms to form a mixture of distorted edge and corner-sharing NSi4 trigonal pyramids. In the second N site, N(2) is bonded in a rectangular see-saw-like geometry to one Si(6) and three equivalent Si(1) atoms. In the third N site, N(3) is bonded in a distorted rectangular see-saw-like geometry to one Si(4), one Si(5), and two equivalent Si(2) atoms. In the fourth N site, N(4) is bonded to one Si(5) and three equivalent Si(1) atoms to form distorted edge-sharing NSi4 trigonal pyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Si(2) atoms. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Si(4) and two equivalent Si(1) atoms.