Materials Data on YSi2Ag3O7 by Materials Project

Abstract

YAg3Si2O7 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded to six O2- atoms to form YO6 octahedra that share corners with six equivalent SiO4 tetrahedra. There are three shorter (2.28 Å) and three longer (2.29 Å) Y–O bond lengths. In the second Y3+ site, Y3+ is bonded to six equivalent O2- atoms to form distorted YO6 pentagonal pyramids that share corners with six equivalent SiO4 tetrahedra. All Y–O bond lengths are 2.30 Å. There are four inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ag–O bond lengths are 2.60 Å. In the second Ag1+ site, Ag1+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ag–O bond lengths are 2.67 Å. In the third Ag1+ site, Ag1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Ag–O bond distances ranging from 2.32–2.69 Å. In the fourth Ag1+ site, Ag1+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All Ag–O bond lengths are 2.34 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent YO6 octahedra, a cornercorner with one YO6 pentagonal pyramid, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–36°. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Y3+, two Ag1+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ag1+ and two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Y3+, two Ag1+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Y3+, two equivalent Ag1+, and one Si4+ atom.