Rb2V3O8 crystallizes in the tetragonal P4bm space group. Rb(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(4) atoms. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form corner-sharing VO4 tetrahedra. In the second V site, V(2) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one V(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one V(1), and one V(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Rb(1) and two equivalent V(1) atoms. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one V(1) atom.
Rb2V3O8 crystallizes in the tetragonal P4bm space group. Rb(1) is bonded in a 6-coordinate geometry to one O(3), two equivalent O(2), and three equivalent O(4) atoms. The Rb(1)-O(3) bond length is 2.93 Å. Both Rb(1)-O(2) bond lengths are 3.01 Å. There is one shorter (2.84 Å) and two longer (2.98 Å) Rb(1)-O(4) bond lengths. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form corner-sharing VO4 tetrahedra. The V(1)-O(3) bond length is 1.81 Å. The V(1)-O(4) bond length is 1.65 Å. Both V(1)-O(2) bond lengths are 1.72 Å. In the second V site, V(2) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(2) atoms. The V(2)-O(1) bond length is 1.62 Å. All V(2)-O(2) bond lengths are 1.95 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one V(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one V(1), and one V(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent Rb(1) and two equivalent V(1) atoms. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one V(1) atom.