Sm3OsO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. In the second Sm site, Sm(2) is bonded to one O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted SmO7 pentagonal bipyramids that share corners with two equivalent Os(1)O6 octahedra, corners with three equivalent Sm(2)O7 pentagonal bipyramids, edges with two equivalent Os(1)O6 octahedra, and edges with two equivalent Sm(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 36°. Os(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form OsO6 octahedra that share corners with two equivalent Os(1)O6 octahedra, corners with four equivalent Sm(2)O7 pentagonal bipyramids, and edges with four equivalent Sm(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sm(2) and two equivalent Os(1) atoms. In the second O site, O(2) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form a mixture of corner and edge-sharing OSm4 tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Os(1) atom.
Sm3OsO7 crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Sm sites. In the first Sm site, Sm(1) is bonded in a body-centered cubic geometry to four equivalent O(2) and four equivalent O(3) atoms. All Sm(1)-O(2) bond lengths are 2.36 Å. All Sm(1)-O(3) bond lengths are 2.70 Å. In the second Sm site, Sm(2) is bonded to one O(1), two equivalent O(2), and four equivalent O(3) atoms to form distorted SmO7 pentagonal bipyramids that share corners with two equivalent Os(1)O6 octahedra, corners with three equivalent Sm(2)O7 pentagonal bipyramids, edges with two equivalent Os(1)O6 octahedra, and edges with two equivalent Sm(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 36°. The Sm(2)-O(1) bond length is 2.55 Å. Both Sm(2)-O(2) bond lengths are 2.27 Å. There are two shorter (2.40 Å) and two longer (2.41 Å) Sm(2)-O(3) bond lengths. Os(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form OsO6 octahedra that share corners with two equivalent Os(1)O6 octahedra, corners with four equivalent Sm(2)O7 pentagonal bipyramids, and edges with four equivalent Sm(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 38°. Both Os(1)-O(1) bond lengths are 1.98 Å. All Os(1)-O(3) bond lengths are 1.97 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sm(2) and two equivalent Os(1) atoms. In the second O site, O(2) is bonded to two equivalent Sm(1) and two equivalent Sm(2) atoms to form a mixture of corner and edge-sharing OSm4 tetrahedra. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Sm(1), two equivalent Sm(2), and one Os(1) atom.