Materials Data on SrAl2B2O7 by Materials Project
SrAl2B2O7 crystallizes in the trigonal R32 space group. The structure is three-dimensional. Sr2+ is bonded to six equivalent O2- atoms to form distorted SrO6 pentagonal pyramids that share corners with six equivalent AlO4 tetrahedra. All Sr–O bond lengths are 2.58 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with three equivalent SrO6 pentagonal pyramids and a cornercorner with one 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 3-coordinate geometry to one Sr2+, one Al3+, and one B3+ atom. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Al3+ atoms.