Materials Data on Al6B5O18 by Materials Project

Al6B5O18 crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. Al is bonded to six O atoms to form a mixture of edge and corner-sharing AlO6 octahedra. The corner-sharing octahedral tilt angles are 65°. There are a spread of Al–O bond distances ranging from 1.85–1.98 Å. There are two inequivalent B sites. In the first B site, B is bonded in a trigonal planar geometry to three equivalent O atoms. All B–O bond lengths are 1.38 Å. In the second B site, B is bonded in a trigonal planar geometry to three O atoms. There is one shorter (1.37 Å) and two longer (1.40 Å) B–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a 3-coordinate geometry to two equivalent Al and one B atom. In the second O site, O is bonded in a water-like geometry to two equivalent Al atoms. In the third O site, O is bonded in a distorted trigonal planar geometry to two equivalent Al and one B atom. In the fourth O site, O is bonded in a trigonal planar geometry to two equivalent Al and one B atom.