Materials Data on Li4Ca3Nb6O20 by Materials Project
Li4Ca3Nb6O20 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.77 Å) and one longer (1.78 Å) Li–O bond length. In the second Li1+ site, Li1+ is bonded in a linear geometry to two O2- atoms. Both Li–O bond lengths are 1.78 Å. There are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with four equivalent CaO12 cuboctahedra, faces with four equivalent CaO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.66–2.84 Å. In the second Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with four equivalent CaO12 cuboctahedra, faces with four equivalent CaO12 cuboctahedra, and faces with eight NbO6 octahedra. There are a spread of Ca–O bond distances ranging from 2.71–2.84 Å. In the third Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.43–2.89 Å. There are six inequivalent Nb5+ sites. In the first Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with four CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–14°. There are a spread of Nb–O bond distances ranging from 1.90–2.09 Å. In the second Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with six NbO6 octahedra and faces with four CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–14°. There are a spread of Nb–O bond distances ranging from 1.90–2.09 Å. In the third Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and faces with four CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Nb–O bond distances ranging from 1.92–2.06 Å. In the fourth Nb5+ site, Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with five NbO6 octahedra and faces with four CaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–13°. There are a spread of Nb–O bond distances ranging from 1.92–2.06 Å. In the fifth Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Nb–O bond distances ranging from 1.90–2.18 Å. In the sixth Nb5+ site, Nb5+ is bonded to six O2- atoms to form corner-sharing NbO6 octahedra. The corner-sharing octahedra tilt angles range from 0–12°. There are a spread of Nb–O bond distances ranging from 1.90–2.19 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Li1+ and one Nb5+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Li1+ and one Nb5+ atom. In the third O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Li1+ and one Nb5+ atom. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Li1+ and one Nb5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two Ca2+ and two Nb5+ atoms. In the sixth O2- site, O2- is bonded in a T-shaped geometry to one Ca2+ and two Nb5+ atoms. In the seventh O2- site, O2- is bonded in a distorted linear geometry to four Ca2+ and two Nb5+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to four Ca2+ and two Nb5+ atoms. In the ninth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ca2+ and two Nb5+ atoms. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ca2+ and two Nb5+ atoms. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two Ca2+ and two Nb5+ atoms.