Cs2Al2B2O7 crystallizes in the monoclinic P2_1/c space group. Cs(1) is bonded in a 11-coordinate geometry to two equivalent O(3), three equivalent O(1), three equivalent O(2), and three equivalent O(4) atoms. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing AlO4 tetrahedra. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to three equivalent Cs(1), one Al(1), and one B(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to three equivalent Cs(1), one Al(1), and one B(1) atom. In the third O site, O(3) is bonded in a linear geometry to four equivalent Cs(1) and two equivalent Al(1) atoms. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to three equivalent Cs(1), one Al(1), and one B(1) atom.
Cs2Al2B2O7 crystallizes in the monoclinic P2_1/c space group. Cs(1) is bonded in a 11-coordinate geometry to two equivalent O(3), three equivalent O(1), three equivalent O(2), and three equivalent O(4) atoms. There is one shorter (3.46 Å) and one longer (3.52 Å) Cs(1)-O(3) bond length. There are a spread of Cs(1)-O(1) bond distances ranging from 3.12-3.58 Å. There are a spread of Cs(1)-O(2) bond distances ranging from 3.16-3.61 Å. There are a spread of Cs(1)-O(4) bond distances ranging from 3.25-3.66 Å. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing AlO4 tetrahedra. The Al(1)-O(1) bond length is 1.77 Å. The Al(1)-O(2) bond length is 1.77 Å. The Al(1)-O(3) bond length is 1.73 Å. The Al(1)-O(4) bond length is 1.76 Å. B(1) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(4) atom. The B(1)-O(1) bond length is 1.39 Å. The B(1)-O(2) bond length is 1.38 Å. The B(1)-O(4) bond length is 1.37 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to three equivalent Cs(1), one Al(1), and one B(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to three equivalent Cs(1), one Al(1), and one B(1) atom. In the third O site, O(3) is bonded in a linear geometry to four equivalent Cs(1) and two equivalent Al(1) atoms. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to three equivalent Cs(1), one Al(1), and one B(1) atom.