Materials Data on Na2Sm2Ti3O10 by Materials Project
Na2Sm2Ti3O10 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Na1+ is bonded in a 5-coordinate geometry to five equivalent O2- atoms. There are one shorter (2.30 Å) and four longer (2.72 Å) Na–O bond lengths. Sm3+ is bonded to twelve O2- atoms to form distorted SmO12 cuboctahedra that share corners with eight equivalent SmO12 cuboctahedra, faces with five equivalent SmO12 cuboctahedra, and faces with four equivalent TiO6 octahedra. There are a spread of Sm–O bond distances ranging from 2.49–2.89 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.77–2.26 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four equivalent TiO6 octahedra and faces with eight equivalent SmO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There is four shorter (1.92 Å) and two longer (1.93 Å) Ti–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Sm3+ and two equivalent Ti4+ atoms. In the second O2- site, O2- is bonded to five equivalent Na1+ and one Ti4+ atom to form a mixture of distorted edge and corner-sharing ONa5Ti octahedra. The corner-sharing octahedral tilt angles are 6°. In the third O2- site, O2- is bonded in a linear geometry to four equivalent Sm3+ and two equivalent Ti4+ atoms. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent Sm3+ and two Ti4+ atoms.