DOI: 10.17188/1723192
title: Materials Data on Al9Si2BO19 by Materials Project

description: Al9BSi2O19 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are seven inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, corners with two equivalent SiO4 tetrahedra, and a cornercorner with one AlO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 50–69°. There is two shorter (1.76 Å) and two longer (1.78 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form distorted AlO4 tetrahedra that share corners with four AlO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–74°. There are a spread of Al–O bond distances ranging from 1.73–1.87 Å. In the third Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two SiO4 tetrahedra, corners with four AlO4 tetrahedra, a cornercorner with one AlO5 trigonal bipyramid, and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.86–2.02 Å. In the fourth Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two SiO4 tetrahedra, corners with four AlO4 tetrahedra, edges with two equivalent AlO6 octahedra, and an edgeedge with one AlO5 trigonal bipyramid. There are a spread of Al–O bond distances ranging from 1.88–1.97 Å. In the fifth Al3+ site, Al3+ is bonded to five O2- atoms to form distorted AlO5 trigonal bipyramids that share corners with two equivalent AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, corners with two equivalent SiO4 tetrahedra, edges with two equivalent AlO6 octahedra, and an edgeedge with one AlO4 tetrahedra. The corner-sharing octahedral tilt angles are 51°. There are a spread of Al–O bond distances ranging from 1.78–2.05 Å. In the sixth Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO6 octahedra, a cornercorner with one SiO4 tetrahedra, and corners with two equivalent AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 53–57°. There is three shorter (1.76 Å) and one longer (1.80 Å) Al–O bond length. In the seventh Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four AlO6 octahedra, corners with three AlO4 tetrahedra, and an edgeedge with one AlO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of Al–O bond distances ranging from 1.74–1.81 Å. B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.37 Å) and two longer (1.40 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 four AlO6 octahedra, a cornercorner with one AlO4 tetrahedra, and corners with two equivalent AlO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 51–54°. There are a spread of Si–O bond distances ranging from 1.59–1.67 Å. In the second Si4+ site, Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four AlO6 octahedra and corners with three AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–55°. There is one shorter (1.61 Å) and three longer (1.65 Å) Si–O bond length. There are fifteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to three Al3+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three Al3+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one B3+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the eighth O2- site, O2- is bonded in a trigonal pyramidal geometry to four Al3+ atoms. In the ninth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the tenth O2- site, O2- is bonded in a trigonal planar geometry to two Al3+ and one B3+ atom. In the eleventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one Si4+ atom. In the twelfth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the thirteenth O2- site, O2- is bonded in a linear geometry to one Al3+ and one Si4+ atom. In the fourteenth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three Al3+ atoms. In the fifteenth O2- site, O2- is bonded in a linear geometry to one Al3+ and one Si4+ atom.