Materials Data on Si2As2O7 by Materials Project

Abstract

Si2As2O7 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one Si2As2O7 sheet oriented in the (-1, 1, 0) direction. there are four inequivalent Si4+ sites. In the first 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 1.63–1.65 Å. In the second Si4+ site, Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.63–1.65 Å. In the third 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 1.63–1.66 Å. In the fourth 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 1.63–1.66 Å. There are four inequivalent As3+ sites. In the first As3+ site, As3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.80–1.85 Å. In the second As3+ site, As3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.81 Å) and two longer (1.83 Å) As–O bond length. In the third As3+ site, As3+ is bonded in a distorted T-shaped geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.80–1.84 Å. In the fourth As3+ site, As3+ is bonded in a distorted trigonal non-coplanar geometry to three O2- atoms. There is one shorter (1.81 Å) and two longer (1.83 Å) As–O bond length. There are fourteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Si4+ and one As3+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Si4+ and one As3+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one As3+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one As3+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Si4+ and one As3+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Si4+ and one As3+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Si4+ and one As3+ atom. 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 120 degrees geometry to one Si4+ and one As3+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Si4+ and one As3+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one As3+ atom. In the twelfth O2- site, O2- is bonded in a bent 120 degrees geometry to one Si4+ and one As3+ atom. In the thirteenth O2- site, O2- is bonded in a bent 120 degrees geometry to two Si4+ atoms. In the fourteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one Si4+ and one As3+ atom.