Rb3HoO3 crystallizes in the monoclinic C2/m space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(2) atoms. In the second Rb site, Rb(2) is bonded in a 4-coordinate geometry to four equivalent O(2) atoms. In the third Rb site, Rb(3) is bonded in a 4-coordinate geometry to four equivalent O(2) atoms. Ho(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form edge-sharing HoO4 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1) and two equivalent Ho(1) atoms. In the second O site, O(2) is bonded in a 7-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), two equivalent Rb(3), and one Ho(1) atom.
Rb3HoO3 crystallizes in the monoclinic C2/m space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1) and four equivalent O(2) atoms. The Rb(1)-O(1) bond length is 2.65 Å. There are two shorter (3.04 Å) and two longer (3.14 Å) Rb(1)-O(2) bond lengths. In the second Rb site, Rb(2) is bonded in a 4-coordinate geometry to four equivalent O(2) atoms. There are two shorter (2.78 Å) and two longer (3.19 Å) Rb(2)-O(2) bond lengths. In the third Rb site, Rb(3) is bonded in a 4-coordinate geometry to four equivalent O(2) atoms. There are two shorter (2.89 Å) and two longer (3.15 Å) Rb(3)-O(2) bond lengths. Ho(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form edge-sharing HoO4 tetrahedra. There is one shorter (2.16 Å) and one longer (2.18 Å) Ho(1)-O(1) bond length. Both Ho(1)-O(2) bond lengths are 2.09 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) and two equivalent Ho(1) atoms. In the second O site, O(2) is bonded in a 7-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), two equivalent Rb(3), and one Ho(1) atom.