Cs2V4O9 crystallizes in the tetragonal P4_2/m space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent O(2) and eight equivalent O(1) atoms. V(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), and three equivalent O(2) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to four equivalent Cs(1) and one V(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cs(1) and three equivalent V(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal pyramidal geometry to four equivalent V(1) atoms.
Cs2V4O9 crystallizes in the tetragonal P4_2/m space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent O(2) and eight equivalent O(1) atoms. Both Cs(1)-O(2) bond lengths are 3.41 Å. There are a spread of Cs(1)-O(1) bond distances ranging from 3.19-3.33 Å. V(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), and three equivalent O(2) atoms. The V(1)-O(1) bond length is 1.64 Å. The V(1)-O(3) bond length is 1.99 Å. There are two shorter (1.93 Å) and one longer (1.97 Å) V(1)-O(2) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to four equivalent Cs(1) and one V(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cs(1) and three equivalent V(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal pyramidal geometry to four equivalent V(1) atoms.