SiO2 is Low Tridymite-like structured and crystallizes in the orthorhombic Pmma space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. There are five 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 bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent Si(2) atoms. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom.
SiO2 is Low Tridymite-like structured and crystallizes in the orthorhombic Pmma space group. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.59 Å. The Si(1)-O(3) bond length is 1.61 Å. Both Si(1)-O(2) bond lengths are 1.62 Å. In the second Si site, Si(2) is bonded to one O(4), one O(5), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. The Si(2)-O(4) bond length is 1.59 Å. The Si(2)-O(5) bond length is 1.61 Å. Both Si(2)-O(2) bond lengths are 1.62 Å. In the third Si site, Si(3) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form corner-sharing SiO4 tetrahedra. Both Si(3)-O(3) bond lengths are 1.61 Å. Both Si(3)-O(5) bond lengths are 1.61 Å. There are five 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 bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent Si(2) atoms. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom.