Materials Data on Ba2CaSm2Ti3(CuO7)2 by Materials Project

Abstract

CaBa2Sm2Cu2Ti3O14 crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.75 Å) and four longer (2.91 Å) Ba–O bond lengths. Ca2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ca–O bond lengths are 2.51 Å. 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 eight TiO6 octahedra. There are a spread of Sm–O bond distances ranging from 2.49–2.90 Å. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with eight equivalent SmO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There is two shorter (1.92 Å) and four longer (1.94 Å) Ti–O bond length. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with five TiO6 octahedra and faces with four equivalent SmO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–24°. There are a spread of Ti–O bond distances ranging from 1.78–2.19 Å. Cu2+ is bonded in a rectangular see-saw-like geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.95 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sm3+ and two equivalent Ti4+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent Ba2+ and one Ti4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent Sm3+ and two Ti4+ atoms. In the fourth O2- site, O2- is bonded to two equivalent Ba2+, two equivalent Ca2+, and two equivalent Cu2+ atoms to form a mixture of distorted edge, face, and corner-sharing OBa2Ca2Cu2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°. In the fifth O2- site, O2- is bonded in a linear geometry to four equivalent Sm3+ and two equivalent Ti4+ atoms.