SiO2 is Low Tridymite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(5), 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(6), and two equivalent O(1) atoms to form corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(3), one O(5), and two equivalent O(7) atoms to form corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(4), one O(6), and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent Si(3) atoms. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fifth O site, O(3) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom.
SiO2 is Low Tridymite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(5), and two equivalent O(2) atoms to form corner-sharing SiO4 tetrahedra. The Si(1)-O(1) bond length is 1.61 Å. The Si(1)-O(5) bond length is 1.61 Å. Both Si(1)-O(2) bond lengths are 1.61 Å. In the second Si site, Si(2) is bonded to one O(4), one O(6), and two equivalent O(1) atoms to form corner-sharing SiO4 tetrahedra. The Si(2)-O(4) bond length is 1.61 Å. The Si(2)-O(6) bond length is 1.62 Å. Both Si(2)-O(1) bond lengths are 1.61 Å. In the third Si site, Si(3) is bonded to one O(3), one O(5), and two equivalent O(7) atoms to form corner-sharing SiO4 tetrahedra. The Si(3)-O(3) bond length is 1.61 Å. The Si(3)-O(5) bond length is 1.61 Å. Both Si(3)-O(7) bond lengths are 1.61 Å. In the fourth Si site, Si(4) is bonded to one O(4), one O(6), and two equivalent O(3) atoms to form corner-sharing SiO4 tetrahedra. The Si(4)-O(4) bond length is 1.62 Å. The Si(4)-O(6) bond length is 1.61 Å. Both Si(4)-O(3) bond lengths are 1.60 Å. There are seven inequivalent O sites. In the first O site, O(6) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the second O site, O(7) is bonded in a bent 150 degrees geometry to two equivalent Si(3) atoms. In the third O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fourth O site, O(2) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fifth O site, O(3) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(4) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom.