SrSm2O4 crystallizes in the orthorhombic Cmcm space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Sm(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing SmO6 octahedra. The corner-sharing octahedral tilt angles range from 0-57°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1) and four equivalent Sm(1) atoms to form distorted OSr2Sm4 octahedra that share corners with two equivalent O(1)Sr2Sm4 octahedra, corners with eight equivalent O(3)Sr2Sm3 trigonal bipyramids, edges with two equivalent O(1)Sr2Sm4 octahedra, edges with four equivalent O(2)Sr2Sm2 tetrahedra, and edges with six equivalent O(3)Sr2Sm3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. In the second O site, O(2) is bonded to two equivalent Sr(1) and two equivalent Sm(1) atoms to form OSr2Sm2 tetrahedra that share corners with two equivalent O(2)Sr2Sm2 tetrahedra, corners with ten equivalent O(3)Sr2Sm3 trigonal bipyramids, edges with four equivalent O(1)Sr2Sm4 octahedra, and edges with two equivalent O(3)Sr2Sm3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Sr(1) and three equivalent Sm(1) atoms to form distorted OSr2Sm3 trigonal bipyramids that share corners with four equivalent O(1)Sr2Sm4 octahedra, corners with five equivalent O(2)Sr2Sm2 tetrahedra, corners with two equivalent O(3)Sr2Sm3 trigonal bipyramids, edges with three equivalent O(1)Sr2Sm4 octahedra,  an edgeedge with one O(2)Sr2Sm2 tetrahedra, and edges with five equivalent O(3)Sr2Sm3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-42°.
SrSm2O4 crystallizes in the orthorhombic Cmcm space group. Sr(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Both Sr(1)-O(1) bond lengths are 3.13 Å. Both Sr(1)-O(2) bond lengths are 2.45 Å. All Sr(1)-O(3) bond lengths are 2.75 Å. Sm(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form a mixture of corner and edge-sharing SmO6 octahedra. The corner-sharing octahedral tilt angles range from 0-57°. The Sm(1)-O(2) bond length is 2.29 Å. Both Sm(1)-O(1) bond lengths are 2.46 Å. There are two shorter (2.34 Å) and one longer (2.41 Å) Sm(1)-O(3) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1) and four equivalent Sm(1) atoms to form distorted OSr2Sm4 octahedra that share corners with two equivalent O(1)Sr2Sm4 octahedra, corners with eight equivalent O(3)Sr2Sm3 trigonal bipyramids, edges with two equivalent O(1)Sr2Sm4 octahedra, edges with four equivalent O(2)Sr2Sm2 tetrahedra, and edges with six equivalent O(3)Sr2Sm3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. In the second O site, O(2) is bonded to two equivalent Sr(1) and two equivalent Sm(1) atoms to form OSr2Sm2 tetrahedra that share corners with two equivalent O(2)Sr2Sm2 tetrahedra, corners with ten equivalent O(3)Sr2Sm3 trigonal bipyramids, edges with four equivalent O(1)Sr2Sm4 octahedra, and edges with two equivalent O(3)Sr2Sm3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Sr(1) and three equivalent Sm(1) atoms to form distorted OSr2Sm3 trigonal bipyramids that share corners with four equivalent O(1)Sr2Sm4 octahedra, corners with five equivalent O(2)Sr2Sm2 tetrahedra, corners with two equivalent O(3)Sr2Sm3 trigonal bipyramids, edges with three equivalent O(1)Sr2Sm4 octahedra,  an edgeedge with one O(2)Sr2Sm2 tetrahedra, and edges with five equivalent O(3)Sr2Sm3 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 10-42°.