Rb3Tm(SO4)3 crystallizes in the monoclinic Cc space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(3), one O(8), and two equivalent O(2) atoms. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), one O(6), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. In the third Rb site, Rb(3) is bonded in a 8-coordinate geometry to one S(1), one O(1), one O(11), one O(12), one O(4), one O(9), and two equivalent O(6) atoms. Tm(1) is bonded to one O(1), one O(10), one O(12), one O(5), one O(7), one O(8), and one O(9) atom to form TmO7 pentagonal bipyramids that share  a cornercorner with one S(2)O4 tetrahedra, corners with two equivalent S(3)O4 tetrahedra, and  an edgeedge with one S(2)O4 tetrahedra. There are three inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one Rb(3), one O(10), one O(5), and one O(6) atom. In the second S site, S(2) is bonded to one O(12), one O(4), one O(7), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Tm(1)O7 pentagonal bipyramid and  an edgeedge with one Tm(1)O7 pentagonal bipyramid. In the third S site, S(3) is bonded to one O(1), one O(11), one O(3), and one O(9) atom to form SO4 tetrahedra that share corners with two equivalent Tm(1)O7 pentagonal bipyramids. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Rb(3), one Tm(1), and one S(3) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Rb(2) and two equivalent Rb(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one S(3) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), and one S(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Tm(1) 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(3), and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Rb(2), one Tm(1), and one S(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Tm(1), and one S(2) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one Rb(3), one Tm(1), and one S(3) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Rb(1), one Tm(1), and one S(1) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), and one S(3) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Rb(3), one Tm(1), and one S(2) atom.
Rb3Tm(SO4)3 crystallizes in the monoclinic Cc space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one O(10), one O(11), one O(3), one O(8), and two equivalent O(2) atoms. The Rb(1)-O(10) bond length is 3.19 Å. The Rb(1)-O(11) bond length is 2.93 Å. The Rb(1)-O(3) bond length is 2.94 Å. The Rb(1)-O(8) bond length is 3.05 Å. There is one shorter (2.77 Å) and one longer (3.03 Å) Rb(1)-O(2) bond length. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to one O(2), one O(4), one O(6), one O(7), one O(8), one O(9), and two equivalent O(3) atoms. The Rb(2)-O(2) bond length is 2.79 Å. The Rb(2)-O(4) bond length is 2.96 Å. The Rb(2)-O(6) bond length is 2.83 Å. The Rb(2)-O(7) bond length is 2.79 Å. The Rb(2)-O(8) bond length is 3.52 Å. The Rb(2)-O(9) bond length is 3.15 Å. There is one shorter (2.90 Å) and one longer (3.02 Å) Rb(2)-O(3) bond length. In the third Rb site, Rb(3) is bonded in a 8-coordinate geometry to one S(1), one O(1), one O(11), one O(12), one O(4), one O(9), and two equivalent O(6) atoms. The Rb(3)-S(1) bond length is 3.31 Å. The Rb(3)-O(1) bond length is 3.07 Å. The Rb(3)-O(11) bond length is 2.85 Å. The Rb(3)-O(12) bond length is 3.36 Å. The Rb(3)-O(4) bond length is 3.00 Å. The Rb(3)-O(9) bond length is 3.17 Å. There is one shorter (2.84 Å) and one longer (3.43 Å) Rb(3)-O(6) bond length. Tm(1) is bonded to one O(1), one O(10), one O(12), one O(5), one O(7), one O(8), and one O(9) atom to form TmO7 pentagonal bipyramids that share  a cornercorner with one S(2)O4 tetrahedra, corners with two equivalent S(3)O4 tetrahedra, and  an edgeedge with one S(2)O4 tetrahedra. The Tm(1)-O(1) bond length is 2.25 Å. The Tm(1)-O(10) bond length is 2.31 Å. The Tm(1)-O(12) bond length is 2.28 Å. The Tm(1)-O(5) bond length is 2.24 Å. The Tm(1)-O(7) bond length is 2.33 Å. The Tm(1)-O(8) bond length is 2.53 Å. The Tm(1)-O(9) bond length is 2.32 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a trigonal non-coplanar geometry to one Rb(3), one O(10), one O(5), and one O(6) atom. The S(1)-O(10) bond length is 1.53 Å. The S(1)-O(5) bond length is 1.53 Å. The S(1)-O(6) bond length is 1.49 Å. In the second S site, S(2) is bonded to one O(12), one O(4), one O(7), and one O(8) atom to form SO4 tetrahedra that share  a cornercorner with one Tm(1)O7 pentagonal bipyramid and  an edgeedge with one Tm(1)O7 pentagonal bipyramid. The S(2)-O(12) bond length is 1.50 Å. The S(2)-O(4) bond length is 1.47 Å. The S(2)-O(7) bond length is 1.51 Å. The S(2)-O(8) bond length is 1.50 Å. In the third S site, S(3) is bonded to one O(1), one O(11), one O(3), and one O(9) atom to form SO4 tetrahedra that share corners with two equivalent Tm(1)O7 pentagonal bipyramids. The S(3)-O(1) bond length is 1.53 Å. The S(3)-O(11) bond length is 1.47 Å. The S(3)-O(3) bond length is 1.47 Å. The S(3)-O(9) bond length is 1.51 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Rb(3), one Tm(1), and one S(3) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Rb(2) and two equivalent Rb(1) atoms. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), two equivalent Rb(2), and one S(3) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), and one S(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Tm(1) 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(3), and one S(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Rb(2), one Tm(1), and one S(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), one Tm(1), and one S(2) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one Rb(3), one Tm(1), and one S(3) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one Rb(1), one Tm(1), and one S(1) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), and one S(3) atom. In the twelfth O site, O(12) is bonded in a distorted bent 150 degrees geometry to one Rb(3), one Tm(1), and one S(2) atom.