Rb3FeO3 crystallizes in the monoclinic P2_1/c 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), two equivalent O(2), and two equivalent O(3) atoms. In the second Rb site, Rb(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(2) atoms. In the third Rb site, Rb(3) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. Fe(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form edge-sharing FeO4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), one Rb(2), two equivalent Rb(3), and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing ORb4Fe2 octahedra. The corner-sharing octahedral tilt angles are 61°. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Rb(3), two equivalent Rb(1), two equivalent Rb(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Rb(2), one Rb(3), two equivalent Rb(1), and one Fe(1) atom.
Rb3FeO3 crystallizes in the monoclinic P2_1/c 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), two equivalent O(2), and two equivalent O(3) atoms. The Rb(1)-O(1) bond length is 2.85 Å. There is one shorter (2.88 Å) and one longer (3.11 Å) Rb(1)-O(2) bond length. There is one shorter (2.80 Å) and one longer (3.11 Å) Rb(1)-O(3) bond length. In the second Rb site, Rb(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(2) atoms. The Rb(2)-O(1) bond length is 3.04 Å. The Rb(2)-O(3) bond length is 2.71 Å. There is one shorter (2.95 Å) and one longer (3.17 Å) Rb(2)-O(2) bond length. In the third Rb site, Rb(3) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Rb(3)-O(2) bond length is 2.99 Å. The Rb(3)-O(3) bond length is 2.92 Å. There is one shorter (2.87 Å) and one longer (3.03 Å) Rb(3)-O(1) bond length. Fe(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form edge-sharing FeO4 tetrahedra. The Fe(1)-O(2) bond length is 1.89 Å. The Fe(1)-O(3) bond length is 1.86 Å. There is one shorter (1.99 Å) and one longer (2.01 Å) Fe(1)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Rb(1), one Rb(2), two equivalent Rb(3), and two equivalent Fe(1) atoms to form a mixture of distorted edge and corner-sharing ORb4Fe2 octahedra. The corner-sharing octahedral tilt angles are 61°. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Rb(3), two equivalent Rb(1), two equivalent Rb(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Rb(2), one Rb(3), two equivalent Rb(1), and one Fe(1) atom.