SiO2 is quartz (alpha)-like structured and crystallizes in the triclinic P-1 space group. There are nine inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(17), one O(2), and one O(8) atom to form distorted corner-sharing SiO4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(14), one O(16), and one O(9) atom to form distorted corner-sharing SiO4 tetrahedra. In the third Si site, Si(3) is bonded to one O(15), one O(18), one O(3), and one O(7) atom to form distorted corner-sharing SiO4 tetrahedra. In the fourth Si site, Si(4) is bonded to one O(11), one O(16), one O(2), and one O(5) atom to form distorted corner-sharing SiO4 tetrahedra. In the fifth Si site, Si(5) is bonded to one O(10), one O(17), one O(3), and one O(4) atom to form distorted corner-sharing SiO4 tetrahedra. In the sixth Si site, Si(6) is bonded to one O(1), one O(12), one O(18), and one O(6) atom to form distorted corner-sharing SiO4 tetrahedra. In the seventh Si site, Si(7) is bonded to one O(10), one O(14), one O(5), and one O(8) atom to form distorted corner-sharing SiO4 tetrahedra. In the eighth Si site, Si(8) is bonded to one O(11), one O(13), one O(6), and one O(7) atom to form distorted corner-sharing SiO4 tetrahedra. In the ninth Si site, Si(9) is bonded to one O(12), one O(15), one O(4), and one O(9) atom to form distorted corner-sharing SiO4 tetrahedra. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(5) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(9) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(7) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(8) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(7) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(9) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(8) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(9) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(8) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(7) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(9) atom. In the sixteenth O site, O(16) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(6) atom.
SiO2 is quartz (alpha)-like structured and crystallizes in the triclinic P-1 space group. There are nine inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(13), one O(17), one O(2), and one O(8) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(1)-O(13) bond length is 1.65 Å. The Si(1)-O(17) bond length is 1.65 Å. The Si(1)-O(2) bond length is 1.65 Å. The Si(1)-O(8) bond length is 1.65 Å. In the second Si site, Si(2) is bonded to one O(1), one O(14), one O(16), and one O(9) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(2)-O(1) bond length is 1.65 Å. The Si(2)-O(14) bond length is 1.65 Å. The Si(2)-O(16) bond length is 1.69 Å. The Si(2)-O(9) bond length is 1.66 Å. In the third Si site, Si(3) is bonded to one O(15), one O(18), one O(3), and one O(7) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(3)-O(15) bond length is 1.64 Å. The Si(3)-O(18) bond length is 1.64 Å. The Si(3)-O(3) bond length is 1.67 Å. The Si(3)-O(7) bond length is 1.66 Å. In the fourth Si site, Si(4) is bonded to one O(11), one O(16), one O(2), and one O(5) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(4)-O(11) bond length is 1.68 Å. The Si(4)-O(16) bond length is 1.65 Å. The Si(4)-O(2) bond length is 1.66 Å. The Si(4)-O(5) bond length is 1.63 Å. In the fifth Si site, Si(5) is bonded to one O(10), one O(17), one O(3), and one O(4) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(5)-O(10) bond length is 1.67 Å. The Si(5)-O(17) bond length is 1.65 Å. The Si(5)-O(3) bond length is 1.66 Å. The Si(5)-O(4) bond length is 1.62 Å. In the sixth Si site, Si(6) is bonded to one O(1), one O(12), one O(18), and one O(6) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(6)-O(1) bond length is 1.66 Å. The Si(6)-O(12) bond length is 1.70 Å. The Si(6)-O(18) bond length is 1.65 Å. The Si(6)-O(6) bond length is 1.64 Å. In the seventh Si site, Si(7) is bonded to one O(10), one O(14), one O(5), and one O(8) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(7)-O(10) bond length is 1.65 Å. The Si(7)-O(14) bond length is 1.67 Å. The Si(7)-O(5) bond length is 1.66 Å. The Si(7)-O(8) bond length is 1.66 Å. In the eighth Si site, Si(8) is bonded to one O(11), one O(13), one O(6), and one O(7) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(8)-O(11) bond length is 1.64 Å. The Si(8)-O(13) bond length is 1.65 Å. The Si(8)-O(6) bond length is 1.66 Å. The Si(8)-O(7) bond length is 1.63 Å. In the ninth Si site, Si(9) is bonded to one O(12), one O(15), one O(4), and one O(9) atom to form distorted corner-sharing SiO4 tetrahedra. The Si(9)-O(12) bond length is 1.64 Å. The Si(9)-O(15) bond length is 1.66 Å. The Si(9)-O(4) bond length is 1.66 Å. The Si(9)-O(9) bond length is 1.63 Å. There are eighteen inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(6) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(5) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(9) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(7) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(8) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(8) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(7) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(9) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Si(5) and one Si(7) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Si(4) and one Si(8) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(6) and one Si(9) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(8) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(7) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(9) atom. In the sixteenth O site, O(16) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. In the seventeenth O site, O(17) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(5) atom. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Si(3) and one Si(6) atom.