Materials Data on BaAl4O7 by Materials Project

Abstract

BaAl4O7 crystallizes in the orthorhombic Pmc2_1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.86–3.35 Å. In the second Ba2+ site, Ba2+ is bonded in a 5-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.93–3.46 Å. There are four inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.80 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. There is two shorter (1.75 Å) and two longer (1.80 Å) Al–O bond length. In the third Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.81 Å. In the fourth Al3+ site, Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.81 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two Al3+ atoms. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two Al3+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ba2+ and two Al3+ atoms. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two equivalent Al3+ atoms. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two equivalent Al3+ atoms. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Ba2+ and two Al3+ atoms. In the eighth O2- site, O2- is bonded in a trigonal planar geometry to three Al3+ atoms.