Materials Data on Sm2Ti12(CuO4)9 by Materials Project
Sm2Ti12(CuO4)9 crystallizes in the trigonal P-3 space group. The structure is three-dimensional. Sm3+ is bonded to twelve O2- atoms to form SmO12 cuboctahedra that share faces with eight TiO6 octahedra. There are a spread of Sm–O bond distances ranging from 2.57–2.59 Å. There are four 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 a faceface with one SmO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 38–43°. There are a spread of Ti–O bond distances ranging from 1.89–2.09 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with two equivalent SmO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 38–40°. There is two shorter (1.97 Å) and four longer (1.98 Å) Ti–O bond length. In the third Ti4+ site, Ti4+ is bonded to six equivalent O2- atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 41°. All Ti–O bond lengths are 1.98 Å. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra and faces with two equivalent SmO12 cuboctahedra. The corner-sharing octahedral tilt angles are 39°. There is three shorter (1.95 Å) and three longer (2.01 Å) Ti–O bond length. There are two inequivalent Cu2+ sites. In the first Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is one shorter (1.96 Å) and three longer (1.97 Å) Cu–O bond length. In the second Cu2+ site, Cu2+ is bonded in a distorted square co-planar geometry to four O2- atoms. There is two shorter (1.98 Å) and two longer (1.99 Å) Cu–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ti4+ and one Cu2+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Sm3+, two Ti4+, and one Cu2+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Sm3+, two Ti4+, and one Cu2+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to one Sm3+, two Ti4+, and one Cu2+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Ti4+ and one Cu2+ atom. In the sixth O2- site, O2- is bonded in a 4-coordinate geometry to one Sm3+, two Ti4+, and one Cu2+ atom.