Rb2Fe2O3 crystallizes in the orthorhombic Pnma space group. There are two 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 7-coordinate geometry to three equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(2) atoms. In the second Fe site, Fe(2) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), three equivalent Rb(2), one Fe(1), and one Fe(2) atom to form a mixture of distorted edge and corner-sharing ORb4Fe2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Fe(1), and one Fe(2) atom.
Rb2Fe2O3 crystallizes in the orthorhombic Pnma space group. There are two 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 3.10 Å. There are two shorter (2.95 Å) and two longer (2.96 Å) Rb(1)-O(2) bond lengths. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to three equivalent O(1) and four equivalent O(2) atoms. There is one shorter (2.96 Å) and two longer (3.19 Å) Rb(2)-O(1) bond lengths. There are two shorter (3.31 Å) and two longer (3.47 Å) Rb(2)-O(2) bond lengths. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(2) atoms. The Fe(1)-O(1) bond length is 1.94 Å. Both Fe(1)-O(2) bond lengths are 1.92 Å. In the second Fe site, Fe(2) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(2) atoms. The Fe(2)-O(1) bond length is 1.94 Å. Both Fe(2)-O(2) bond lengths are 1.92 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), three equivalent Rb(2), one Fe(1), and one Fe(2) atom to form a mixture of distorted edge and corner-sharing ORb4Fe2 octahedra. The corner-sharing octahedral tilt angles are 3°. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Fe(1), and one Fe(2) atom.