Materials Data on CaTi4(CuO4)3 by Materials Project
CaCu3Ti4O12 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share faces with eight TiO6 octahedra. There are six shorter (2.61 Å) and six longer (2.62 Å) Ca–O bond lengths. In the second Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share faces with eight TiO6 octahedra. There are six shorter (2.61 Å) and six longer (2.62 Å) Ca–O bond lengths. 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 equivalent TiO6 octahedra and faces with two CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 39–40°. There is three shorter (1.98 Å) and three longer (1.99 Å) Ti–O bond length. 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 CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 39–40°. There is three shorter (1.98 Å) and three longer (1.99 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. All Cu–O bond lengths are 1.98 Å. In the second Cu2+ site, Cu2+ is bonded in a square co-planar geometry to four O2- atoms. All Cu–O bond lengths are 1.98 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two equivalent Ti4+, and one Cu2+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two Ti4+, and one Cu2+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, two Ti4+, and one Cu2+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Ca2+, two equivalent Ti4+, and one Cu2+ atom.