Rb2S2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(5), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(3), one O(6), one O(7), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form corner-sharing SO4 tetrahedra. In the second S site, S(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form corner-sharing SO4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Rb(1), one S(1), and one S(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one S(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one S(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Rb(2) and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one S(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one S(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one S(2) atom.
Rb2S2O7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(5), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. The Rb(1)-O(1) bond length is 3.26 Å. The Rb(1)-O(2) bond length is 2.90 Å. The Rb(1)-O(5) bond length is 2.87 Å. There is one shorter (2.87 Å) and one longer (3.41 Å) Rb(1)-O(3) bond length. There is one shorter (2.93 Å) and one longer (2.96 Å) Rb(1)-O(6) bond length. There is one shorter (2.95 Å) and one longer (3.20 Å) Rb(1)-O(7) bond length. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(3), one O(6), one O(7), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. The Rb(2)-O(3) bond length is 2.92 Å. The Rb(2)-O(6) bond length is 2.88 Å. The Rb(2)-O(7) bond length is 3.01 Å. There is one shorter (2.99 Å) and one longer (3.14 Å) Rb(2)-O(2) bond length. There is one shorter (2.90 Å) and one longer (3.29 Å) Rb(2)-O(4) bond length. There is one shorter (2.93 Å) and one longer (2.94 Å) Rb(2)-O(5) bond length. There are two inequivalent S sites. In the first S site, S(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form corner-sharing SO4 tetrahedra. The S(1)-O(1) bond length is 1.66 Å. The S(1)-O(2) bond length is 1.45 Å. The S(1)-O(4) bond length is 1.44 Å. The S(1)-O(5) bond length is 1.45 Å. In the second S site, S(2) is bonded to one O(1), one O(3), one O(6), and one O(7) atom to form corner-sharing SO4 tetrahedra. The S(2)-O(1) bond length is 1.65 Å. The S(2)-O(3) bond length is 1.44 Å. The S(2)-O(6) bond length is 1.45 Å. The S(2)-O(7) bond length is 1.44 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Rb(1), one S(1), and one S(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one S(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one S(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Rb(2) and one S(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one S(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one S(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one S(2) atom.