Materials Data on BaAl2B2O7 by Materials Project
BaAl2B2O7 crystallizes in the trigonal R32 space group. The structure is three-dimensional. Ba2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ba–O bond lengths are 2.78 Å. Al3+ is bonded to four O2- atoms to form corner-sharing AlO4 tetrahedra. There is one shorter (1.69 Å) and three longer (1.79 Å) Al–O bond length. B3+ is bonded in a trigonal planar geometry to three equivalent O2- atoms. All B–O bond lengths are 1.38 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Al3+, and one B3+ atom. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Al3+ atoms.