Si3O crystallizes in the monoclinic C2/c space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a single-bond geometry to two equivalent Si(3) and one O(1) atom. In the second Si site, Si(2) is bonded in a single-bond geometry to two equivalent Si(3) and one O(2) atom. In the third Si site, Si(3) is bonded to two equivalent Si(1) and two equivalent Si(2) atoms to form corner-sharing SiSi4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Si(2) atoms.
Si3O crystallizes in the monoclinic C2/c space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded in a single-bond geometry to two equivalent Si(3) and one O(1) atom. Both Si(1)-Si(3) bond lengths are 2.49 Å. The Si(1)-O(1) bond length is 1.61 Å. In the second Si site, Si(2) is bonded in a single-bond geometry to two equivalent Si(3) and one O(2) atom. There is one shorter (2.46 Å) and one longer (2.49 Å) Si(2)-Si(3) bond length. The Si(2)-O(2) bond length is 1.64 Å. In the third Si site, Si(3) is bonded to two equivalent Si(1) and two equivalent Si(2) atoms to form corner-sharing SiSi4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Si(2) atoms.