RbOs2O9 crystallizes in the orthorhombic Pna2_1 space group. Rb(1) is bonded in a 14-coordinate geometry to one O(4), one O(5), one O(8), one O(9), two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded to one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form distorted corner-sharing OsO5 trigonal bipyramids. In the second Os site, Os(2) is bonded to one O(1), one O(2), one O(5), one O(7), and one O(9) atom to form distorted corner-sharing OsO5 trigonal bipyramids. There are nine inequivalent O sites. In the first O site, O(6) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(1) atom. In the second O site, O(7) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(2) atom. In the third O site, O(8) is bonded in a single-bond geometry to one Rb(1) and one Os(1) atom. In the fourth O site, O(1) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(2) atom. In the fifth O site, O(9) is bonded in a 2-coordinate geometry to one Rb(1), one Os(1), and one Os(2) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Os(2) atom. In the seventh O site, O(3) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(1) atom. In the eighth O site, O(4) is bonded in a single-bond geometry to one Rb(1) and one Os(1) atom. In the ninth O site, O(5) is bonded in a distorted single-bond geometry to one Rb(1) and one Os(2) atom.
RbOs2O9 crystallizes in the orthorhombic Pna2_1 space group. Rb(1) is bonded in a 14-coordinate geometry to one O(4), one O(5), one O(8), one O(9), two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. The Rb(1)-O(4) bond length is 3.33 Å. The Rb(1)-O(5) bond length is 3.17 Å. The Rb(1)-O(8) bond length is 3.13 Å. The Rb(1)-O(9) bond length is 3.37 Å. There is one shorter (3.46 Å) and one longer (3.58 Å) Rb(1)-O(1) bond length. There is one shorter (3.09 Å) and one longer (3.37 Å) Rb(1)-O(2) bond length. There is one shorter (3.30 Å) and one longer (3.33 Å) Rb(1)-O(3) bond length. There is one shorter (3.27 Å) and one longer (3.38 Å) Rb(1)-O(6) bond length. There is one shorter (3.33 Å) and one longer (3.47 Å) Rb(1)-O(7) bond length. There are two inequivalent Os sites. In the first Os site, Os(1) is bonded to one O(3), one O(4), one O(6), one O(8), and one O(9) atom to form distorted corner-sharing OsO5 trigonal bipyramids. The Os(1)-O(3) bond length is 1.74 Å. The Os(1)-O(4) bond length is 1.74 Å. The Os(1)-O(6) bond length is 1.75 Å. The Os(1)-O(8) bond length is 1.75 Å. The Os(1)-O(9) bond length is 2.21 Å. In the second Os site, Os(2) is bonded to one O(1), one O(2), one O(5), one O(7), and one O(9) atom to form distorted corner-sharing OsO5 trigonal bipyramids. The Os(2)-O(1) bond length is 1.75 Å. The Os(2)-O(2) bond length is 1.74 Å. The Os(2)-O(5) bond length is 1.74 Å. The Os(2)-O(7) bond length is 1.74 Å. The Os(2)-O(9) bond length is 2.26 Å. There are nine inequivalent O sites. In the first O site, O(6) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(1) atom. In the second O site, O(7) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(2) atom. In the third O site, O(8) is bonded in a single-bond geometry to one Rb(1) and one Os(1) atom. In the fourth O site, O(1) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(2) atom. In the fifth O site, O(9) is bonded in a 2-coordinate geometry to one Rb(1), one Os(1), and one Os(2) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Os(2) atom. In the seventh O site, O(3) is bonded in a single-bond geometry to two equivalent Rb(1) and one Os(1) atom. In the eighth O site, O(4) is bonded in a single-bond geometry to one Rb(1) and one Os(1) atom. In the ninth O site, O(5) is bonded in a distorted single-bond geometry to one Rb(1) and one Os(2) atom.