Materials Data on La8Al7GaO24 by Materials Project

Abstract

La8GaAl7O24 is (Cubic) Perovskite-derived structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with twelve equivalent LaO12 cuboctahedra, faces with six equivalent LaO12 cuboctahedra, a faceface with one GaO6 octahedra, and faces with seven AlO6 octahedra. There are three shorter (2.70 Å) and nine longer (2.71 Å) La–O bond lengths. Ga3+ is bonded to six equivalent O2- atoms to form GaO6 octahedra that share corners with six equivalent AlO6 octahedra and faces with eight equivalent LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Ga–O bond lengths are 1.96 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent GaO6 octahedra, corners with four equivalent AlO6 octahedra, and faces with eight equivalent LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There is two shorter (1.87 Å) and four longer (1.92 Å) Al–O bond length. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six AlO6 octahedra and faces with eight equivalent LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Al–O bond lengths are 1.91 Å. In the third Al3+ site, Al3+ is bonded to six equivalent O2- atoms to form AlO6 octahedra that share corners with six equivalent AlO6 octahedra and faces with eight equivalent LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. All Al–O bond lengths are 1.91 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent La3+, one Ga3+, and one Al3+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four equivalent La3+ and two Al3+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent La3+ and two Al3+ atoms.