Rb2SnO3 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to two equivalent O(3) and three equivalent O(2) atoms to form distorted RbO5 trigonal bipyramids that share corners with four equivalent Rb(2)O7 pentagonal bipyramids, corners with five equivalent Sn(1)O4 tetrahedra, corners with two equivalent Rb(1)O5 trigonal bipyramids, edges with four equivalent Rb(2)O7 pentagonal bipyramids, and edges with three equivalent Rb(1)O5 trigonal bipyramids. In the second Rb site, Rb(2) is bonded to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms to form distorted RbO7 pentagonal bipyramids that share corners with four equivalent Rb(2)O7 pentagonal bipyramids,  a cornercorner with one Sn(1)O4 tetrahedra, corners with four equivalent Rb(1)O5 trigonal bipyramids, edges with three equivalent Rb(2)O7 pentagonal bipyramids, edges with four equivalent Sn(1)O4 tetrahedra, and edges with four equivalent Rb(1)O5 trigonal bipyramids. Sn(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SnO4 tetrahedra that share  a cornercorner with one Rb(2)O7 pentagonal bipyramid, corners with two equivalent Sn(1)O4 tetrahedra, corners with five equivalent Rb(1)O5 trigonal bipyramids, and edges with four equivalent Rb(2)O7 pentagonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(2) and two equivalent Sn(1) atoms. In the second O site, O(2) is bonded to two equivalent Rb(2), three equivalent Rb(1), and one Sn(1) atom to form a mixture of distorted corner and edge-sharing ORb5Sn octahedra. The corner-sharing octahedral tilt angles are 18°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Rb(1), three equivalent Rb(2), and one Sn(1) atom.
Rb2SnO3 crystallizes in the orthorhombic Cmce space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to two equivalent O(3) and three equivalent O(2) atoms to form distorted RbO5 trigonal bipyramids that share corners with four equivalent Rb(2)O7 pentagonal bipyramids, corners with five equivalent Sn(1)O4 tetrahedra, corners with two equivalent Rb(1)O5 trigonal bipyramids, edges with four equivalent Rb(2)O7 pentagonal bipyramids, and edges with three equivalent Rb(1)O5 trigonal bipyramids. There is one shorter (2.90 Å) and one longer (2.94 Å) Rb(1)-O(3) bond length. There is one shorter (3.09 Å) and two longer (3.12 Å) Rb(1)-O(2) bond lengths. In the second Rb site, Rb(2) is bonded to two equivalent O(1), two equivalent O(2), and three equivalent O(3) atoms to form distorted RbO7 pentagonal bipyramids that share corners with four equivalent Rb(2)O7 pentagonal bipyramids,  a cornercorner with one Sn(1)O4 tetrahedra, corners with four equivalent Rb(1)O5 trigonal bipyramids, edges with three equivalent Rb(2)O7 pentagonal bipyramids, edges with four equivalent Sn(1)O4 tetrahedra, and edges with four equivalent Rb(1)O5 trigonal bipyramids. Both Rb(2)-O(1) bond lengths are 3.04 Å. There is one shorter (2.89 Å) and one longer (3.00 Å) Rb(2)-O(2) bond length. There are two shorter (3.12 Å) and one longer (3.26 Å) Rb(2)-O(3) bond length. Sn(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form SnO4 tetrahedra that share  a cornercorner with one Rb(2)O7 pentagonal bipyramid, corners with two equivalent Sn(1)O4 tetrahedra, corners with five equivalent Rb(1)O5 trigonal bipyramids, and edges with four equivalent Rb(2)O7 pentagonal bipyramids. The Sn(1)-O(2) bond length is 1.96 Å. The Sn(1)-O(3) bond length is 1.95 Å. Both Sn(1)-O(1) bond lengths are 2.02 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(2) and two equivalent Sn(1) atoms. In the second O site, O(2) is bonded to two equivalent Rb(2), three equivalent Rb(1), and one Sn(1) atom to form a mixture of distorted corner and edge-sharing ORb5Sn octahedra. The corner-sharing octahedral tilt angles are 18°. In the third O site, O(3) is bonded in a 6-coordinate geometry to two equivalent Rb(1), three equivalent Rb(2), and one Sn(1) atom.