RbCr2FeO8 crystallizes in the orthorhombic Pnma space group. Rb(1) is bonded in a 10-coordinate geometry to one O(2), two equivalent O(4), two equivalent O(5), two equivalent O(6), and three equivalent O(1) atoms. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-40°. In the second Cr site, Cr(2) is bonded to one O(1), one O(3), and two equivalent O(6) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-34°. Fe(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Cr(1)O4 tetrahedra and corners with three equivalent Cr(2)O4 tetrahedra. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(1), and one Fe(1) atom. In the second O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(2), and one Fe(1) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Cr(2) atom. In the fourth O site, O(2) is bonded in a single-bond geometry to one Rb(1) and one Cr(1) atom. In the fifth O site, O(3) is bonded in a linear geometry to one Cr(2) and one Fe(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Cr(1), and one Fe(1) atom.
RbCr2FeO8 crystallizes in the orthorhombic Pnma space group. Rb(1) is bonded in a 10-coordinate geometry to one O(2), two equivalent O(4), two equivalent O(5), two equivalent O(6), and three equivalent O(1) atoms. The Rb(1)-O(2) bond length is 3.04 Å. Both Rb(1)-O(4) bond lengths are 3.34 Å. Both Rb(1)-O(5) bond lengths are 3.26 Å. Both Rb(1)-O(6) bond lengths are 3.08 Å. There is one shorter (2.96 Å) and two longer (3.13 Å) Rb(1)-O(1) bond lengths. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(2), one O(4), and two equivalent O(5) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-40°. The Cr(1)-O(2) bond length is 1.61 Å. The Cr(1)-O(4) bond length is 1.70 Å. Both Cr(1)-O(5) bond lengths are 1.68 Å. In the second Cr site, Cr(2) is bonded to one O(1), one O(3), and two equivalent O(6) atoms to form CrO4 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-34°. The Cr(2)-O(1) bond length is 1.63 Å. The Cr(2)-O(3) bond length is 1.66 Å. Both Cr(2)-O(6) bond lengths are 1.69 Å. Fe(1) is bonded to one O(3), one O(4), two equivalent O(5), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with three equivalent Cr(1)O4 tetrahedra and corners with three equivalent Cr(2)O4 tetrahedra. The Fe(1)-O(3) bond length is 2.01 Å. The Fe(1)-O(4) bond length is 2.04 Å. Both Fe(1)-O(5) bond lengths are 2.02 Å. Both Fe(1)-O(6) bond lengths are 2.00 Å. There are six inequivalent O sites. In the first O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(1), and one Fe(1) atom. In the second O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Cr(2), and one Fe(1) atom. In the third O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Cr(2) atom. In the fourth O site, O(2) is bonded in a single-bond geometry to one Rb(1) and one Cr(1) atom. In the fifth O site, O(3) is bonded in a linear geometry to one Cr(2) and one Fe(1) atom. In the sixth O site, O(4) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Cr(1), and one Fe(1) atom.