DOI: 10.17188/1687434
title: Materials Data on BaYb6Si7O24 by Materials Project

description: BaYb6Si7O24 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.21 Å. There are three inequivalent Yb3+ sites. In the first Yb3+ site, Yb3+ is bonded to six O2- atoms to form YbO6 octahedra that share corners with six SiO4 tetrahedra and edges with two YbO6 octahedra. There are a spread of Yb–O bond distances ranging from 2.30–2.38 Å. In the second Yb3+ site, Yb3+ is bonded to six O2- atoms to form distorted YbO6 octahedra that share corners with six SiO4 tetrahedra, an edgeedge with one YbO6 octahedra, and edges with two equivalent YbO6 pentagonal pyramids. There are a spread of Yb–O bond distances ranging from 2.30–2.37 Å. In the third Yb3+ site, Yb3+ is bonded to six O2- atoms to form distorted YbO6 pentagonal pyramids that share corners with six SiO4 tetrahedra, edges with two equivalent YbO6 octahedra, and an edgeedge with one YbO6 pentagonal pyramid. There are a spread of Yb–O bond distances ranging from 2.31–2.36 Å. There are four inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with two equivalent YbO6 octahedra, corners with four equivalent YbO6 pentagonal pyramids, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–51°. There is three shorter (1.63 Å) and one longer (1.65 Å) Si–O bond length. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four YbO6 octahedra, a cornercorner with one YbO6 pentagonal pyramid, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 43–52°. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four YbO6 octahedra, a cornercorner with one YbO6 pentagonal pyramid, and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 42–59°. There are a spread of Si–O bond distances ranging from 1.62–1.69 Å. In the fourth Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent YbO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–53°. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. There are thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two Yb3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two Yb3+ and one Si4+ atom. In the third O2- site, O2- is bonded in a linear geometry to two Si4+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Yb3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, one Yb3+, and one Si4+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Yb3+ and one Si4+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Yb3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, one Yb3+, and one Si4+ atom. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Yb3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Yb3+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+ and two Si4+ atoms. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, two equivalent Yb3+, and one Si4+ atom. In the thirteenth O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, two equivalent Yb3+, and one Si4+ atom.