Materials Data on Sm3MgTi4O14 by Materials Project

MgSm3Ti4O14 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg is bonded to eight O atoms to form distorted MgO8 hexagonal bipyramids that share edges with six equivalent SmO8 hexagonal bipyramids and edges with six equivalent TiO6 octahedra. There are two shorter (1.99 Å) and six longer (2.60 Å) Mg–O bond lengths. Sm is bonded to eight O atoms to form SmO8 hexagonal bipyramids that share edges with two equivalent MgO8 hexagonal bipyramids, edges with four equivalent SmO8 hexagonal bipyramids, and edges with six TiO6 octahedra. There are a spread of Sm–O bond distances ranging from 2.30–2.52 Å. There are two inequivalent Ti sites. In the first Ti site, Ti is bonded to six equivalent O atoms to form TiO6 octahedra that share corners with six equivalent TiO6 octahedra and edges with six equivalent SmO8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 49°. All Ti–O bond lengths are 1.97 Å. In the second Ti site, Ti is bonded to six O atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, edges with two equivalent MgO8 hexagonal bipyramids, and edges with four equivalent SmO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 44–49°. There is two shorter (1.96 Å) and four longer (1.97 Å) Ti–O bond length. There are three inequivalent O sites. In the first O site, O is bonded to one Mg and three equivalent Sm atoms to form a mixture of edge and corner-sharing OSm3Mg tetrahedra. In the second O site, O is bonded in a 4-coordinate geometry to one Mg, one Sm, and two equivalent Ti atoms. In the third O site, O is bonded to two equivalent Sm and two Ti atoms to form a mixture of distorted edge and corner-sharing OSm2Ti2 tetrahedra.