Materials Data on Al4Bi2O9 by Materials Project

Abstract

Bi2Al4O9 crystallizes in the orthorhombic Pbam space group. The structure is three-dimensional. there are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four equivalent AlO6 octahedra and a cornercorner with one AlO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–56°. There are a spread of Al–O bond distances ranging from 1.75–1.80 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with four equivalent AlO4 tetrahedra and edges with two equivalent AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.88–1.97 Å. Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.19–2.89 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Al3+ and two equivalent Bi3+ 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 3-coordinate geometry to two Al3+ and two equivalent Bi3+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent Al3+ atoms.