DOE OSTI2020
SiO2 crystallizes in the triclinic P1 space group. The structure is two-dimensional and consists of two Si2O5 ribbons oriented in the (0, 1, 0) direction and one Si13O25 sheet oriented in the (0, 0, 1) direction. In each Si2O5 ribbon, there are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.61 Å) and three longer (1.65 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.56–1.61 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Si4+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one Si4+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Si4+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the Si13O25 sheet, there are twenty-six inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.62 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.62 Å) Si–O bond length. In the third Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the fourth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. In the fifth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.65 Å) and one longer (1.66 Å) Si–O bond length. In the sixth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.61 Å) and two longer (1.62 Å) Si–O bond length. In the seventh Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.62 Å. In the eighth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.61 Å) and two longer (1.62 Å) Si–O bond length. In the ninth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the tenth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.62 Å) Si–O bond length. In the eleventh Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is three shorter (1.62 Å) and one longer (1.63 Å) Si–O bond length. In the twelfth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the thirteenth Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is one shorter (1.63 Å) and three longer (1.64 Å) Si–O bond length. In the fourteenth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.64 Å. In the fifteenth Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. In the sixteenth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.62 Å. In the seventeenth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is three shorter (1.61 Å) and one longer (1.62 Å) Si–O bond length. In the eighteenth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is three shorter (1.61 Å) and one longer (1.62 Å) Si–O bond length. In the nineteenth Si4+ site, Si4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.53–1.63 Å. In the twentieth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.61 Å) and three longer (1.62 Å) Si–O bond length. In the twenty-first Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the twenty-second Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.61 Å) and two longer (1.62 Å) Si–O bond length. In the twenty-third Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.64–1.66 Å. In the twenty-fourth Si4+ site, Si4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. In the twenty-fifth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.61 Å) and two longer (1.62 Å) Si–O bond length. In the twenty-sixth Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.62 Å. There are fifty inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the sixth O2- site, O2- is bonded in a single-bond geometry to one Si4+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fifteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the sixteenth O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the seventeenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the eighteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the nineteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twentieth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-second O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-third O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Si4+ atoms. In the twenty-sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the twenty-ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirtieth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-second O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-third O2- site, O2- is bonded in a single-bond geometry to one Si4+ atom. In the thirty-fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-fifth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the thirty-ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fortieth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the forty-first O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the forty-second O2- site, O2- is bonded in a single-bond geometry to one Si4+ atom. In the forty-third O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the forty-fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the forty-fifth O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the forty-sixth O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the forty-seventh O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the forty-eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the forty-ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms. In the fiftieth O2- site, O2- is bonded in a bent 150 degrees geometry to two Si4+ atoms.