RbCrO8(NH4)2 crystallizes in the tetragonal I-42m space group. The structure consists of four ammonium molecules inside a RbCrO8 framework. In the RbCrO8 framework, Rb(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form RbO8 hexagonal bipyramids that share corners with four equivalent Cr(1)O8 hexagonal bipyramids and edges with two equivalent Cr(1)O8 hexagonal bipyramids. Cr(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted CrO8 hexagonal bipyramids that share corners with four equivalent Rb(1)O8 hexagonal bipyramids and edges with two equivalent Rb(1)O8 hexagonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one Cr(1), and one O(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Rb(1), one Cr(1), and one O(1) atom.
RbCrO8(NH4)2 crystallizes in the tetragonal I-42m space group. The structure consists of four ammonium molecules inside a RbCrO8 framework. In the RbCrO8 framework, Rb(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form RbO8 hexagonal bipyramids that share corners with four equivalent Cr(1)O8 hexagonal bipyramids and edges with two equivalent Cr(1)O8 hexagonal bipyramids. All Rb(1)-O(1) bond lengths are 3.10 Å. All Rb(1)-O(2) bond lengths are 3.01 Å. Cr(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted CrO8 hexagonal bipyramids that share corners with four equivalent Rb(1)O8 hexagonal bipyramids and edges with two equivalent Rb(1)O8 hexagonal bipyramids. All Cr(1)-O(1) bond lengths are 1.92 Å. All Cr(1)-O(2) bond lengths are 1.98 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one Cr(1), and one O(2) atom. The O(1)-O(2) bond length is 1.46 Å. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Rb(1), one Cr(1), and one O(1) atom.