DOE OSTI2020
SrSm2O4 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Sr2+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.45–3.13 Å. Sm3+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing SmO6 octahedra. The corner-sharing octahedra tilt angles range from 0–57°. There are a spread of Sm–O bond distances ranging from 2.29–2.46 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Sr2+ and four equivalent Sm3+ atoms to form distorted OSr2Sm4 octahedra that share corners with two equivalent OSr2Sm4 octahedra, corners with eight equivalent OSr2Sm3 trigonal bipyramids, edges with two equivalent OSr2Sm4 octahedra, edges with four equivalent OSr2Sm2 tetrahedra, and edges with six equivalent OSr2Sm3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 49°. In the second O2- site, O2- is bonded to two equivalent Sr2+ and two equivalent Sm3+ atoms to form OSr2Sm2 tetrahedra that share corners with two equivalent OSr2Sm2 tetrahedra, corners with ten equivalent OSr2Sm3 trigonal bipyramids, edges with four equivalent OSr2Sm4 octahedra, and edges with two equivalent OSr2Sm3 trigonal bipyramids. In the third O2- site, O2- is bonded to two equivalent Sr2+ and three equivalent Sm3+ atoms to form distorted OSr2Sm3 trigonal bipyramids that share corners with four equivalent OSr2Sm4 octahedra, corners with five equivalent OSr2Sm2 tetrahedra, corners with two equivalent OSr2Sm3 trigonal bipyramids, edges with three equivalent OSr2Sm4 octahedra, an edgeedge with one OSr2Sm2 tetrahedra, and edges with five equivalent OSr2Sm3 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 10–42°.