DOI: 10.17188/1350724
title: Materials Data on Al7Si3BO18 by Materials Project

description: Al7BSi3O18 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six SiO4 tetrahedra and faces with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.89–1.91 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two AlO6 octahedra, corners with three SiO4 tetrahedra, and edges with four AlO6 octahedra. The corner-sharing octahedra tilt angles range from 21–60°. There are a spread of Al–O bond distances ranging from 1.90–1.96 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two AlO6 octahedra, corners with three SiO4 tetrahedra, and edges with four AlO6 octahedra. The corner-sharing octahedra tilt angles range from 21–60°. There are a spread of Al–O bond distances ranging from 1.91–1.95 Å. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with three AlO6 octahedra, corners with three equivalent SiO4 tetrahedra, edges with two equivalent AlO6 octahedra, and a faceface with one AlO6 octahedra. The corner-sharing octahedra tilt angles range from 28–60°. There are a spread of Al–O bond distances ranging from 1.87–1.99 Å. B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.36 Å) and two longer (1.37 Å) B–O bond length. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with eight AlO6 octahedra. The corner-sharing octahedra tilt angles range from 31–60°. There are a spread of Si–O bond distances ranging from 1.64–1.68 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with eight AlO6 octahedra. The corner-sharing octahedra tilt angles range from 30–61°. There are a spread of Si–O bond distances ranging from 1.65–1.70 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Al3+ and one B3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one B3+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Al3+ and one Si4+ atom. In the sixth O2- site, O2- is bonded to four Al3+ atoms to form edge-sharing OAl4 trigonal pyramids. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four equivalent Al3+ atoms. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Al3+ and one Si4+ atom. In the ninth O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a trigonal planar geometry to two Al3+ and one Si4+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom.