Sr2Be2B2O7 crystallizes in the hexagonal P-6c2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to six equivalent O(1) atoms to form distorted SrO6 pentagonal pyramids that share corners with six equivalent Be(1)O4 tetrahedra. In the second Sr site, Sr(2) is bonded in a distorted q6 geometry to three equivalent O(2) and six equivalent O(1) atoms. Be(1) is bonded to one O(2) and three equivalent O(1) atoms to form BeO4 tetrahedra that share corners with three equivalent Sr(1)O6 pentagonal pyramids and  a cornercorner with one Be(1)O4 tetrahedra. B(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(2), one Be(1), and one B(1) atom. In the second O site, O(2) is bonded in a linear geometry to three equivalent Sr(2) and two equivalent Be(1) atoms.
Sr2Be2B2O7 crystallizes in the hexagonal P-6c2 space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to six equivalent O(1) atoms to form distorted SrO6 pentagonal pyramids that share corners with six equivalent Be(1)O4 tetrahedra. All Sr(1)-O(1) bond lengths are 2.53 Å. In the second Sr site, Sr(2) is bonded in a distorted q6 geometry to three equivalent O(2) and six equivalent O(1) atoms. All Sr(2)-O(2) bond lengths are 2.73 Å. All Sr(2)-O(1) bond lengths are 2.79 Å. Be(1) is bonded to one O(2) and three equivalent O(1) atoms to form BeO4 tetrahedra that share corners with three equivalent Sr(1)O6 pentagonal pyramids and  a cornercorner with one Be(1)O4 tetrahedra. The Be(1)-O(2) bond length is 1.58 Å. All Be(1)-O(1) bond lengths are 1.66 Å. B(1) is bonded in a trigonal planar geometry to three equivalent O(1) atoms. All B(1)-O(1) bond lengths are 1.38 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Sr(1), one Sr(2), one Be(1), and one B(1) atom. In the second O site, O(2) is bonded in a linear geometry to three equivalent Sr(2) and two equivalent Be(1) atoms.