Materials Data on LaAlO3 by Materials Project

Abstract

LaAlO3 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent La3+ sites. In the first La3+ site, La3+ is bonded to six O2- atoms to form distorted LaO6 octahedra that share corners with five AlO4 tetrahedra, edges with two equivalent LaO6 octahedra, edges with two equivalent LaO7 pentagonal bipyramids, and an edgeedge with one AlO4 tetrahedra. There are a spread of La–O bond distances ranging from 2.36–2.66 Å. In the second La3+ site, La3+ is bonded to six O2- atoms to form distorted LaO6 octahedra that share corners with five AlO4 tetrahedra, edges with two equivalent LaO6 octahedra, edges with two equivalent LaO7 pentagonal bipyramids, and an edgeedge with one AlO4 tetrahedra. There are a spread of La–O bond distances ranging from 2.42–2.65 Å. In the third La3+ site, La3+ is bonded to seven O2- atoms to form distorted LaO7 pentagonal bipyramids that share corners with four AlO4 tetrahedra, edges with four LaO6 octahedra, edges with two equivalent LaO7 pentagonal bipyramids, and edges with two AlO4 tetrahedra. There are a spread of La–O bond distances ranging from 2.39–2.58 Å. There are three inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four LaO6 octahedra, a cornercorner with one LaO7 pentagonal bipyramid, corners with two AlO4 tetrahedra, and an edgeedge with one LaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 47–67°. There are a spread of Al–O bond distances ranging from 1.76–1.80 Å. In the second Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with four LaO6 octahedra, a cornercorner with one LaO7 pentagonal bipyramid, corners with two AlO4 tetrahedra, and an edgeedge with one LaO7 pentagonal bipyramid. The corner-sharing octahedra tilt angles range from 47–67°. There are a spread of Al–O bond distances ranging from 1.76–1.80 Å. In the third Al3+ site, Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share corners with two LaO6 octahedra, corners with two equivalent LaO7 pentagonal bipyramids, corners with two AlO4 tetrahedra, and edges with two LaO6 octahedra. The corner-sharing octahedra tilt angles range from 56–57°. There are a spread of Al–O bond distances ranging from 1.78–1.80 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Al3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two La3+ and one Al3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two La3+ and one Al3+ atom. In the fourth O2- site, O2- is bonded in a distorted T-shaped geometry to one La3+ and two Al3+ atoms. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Al3+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one La3+ and two Al3+ atoms. In the seventh O2- site, O2- is bonded to three La3+ and one Al3+ atom to form distorted corner-sharing OLa3Al tetrahedra. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one La3+ and two Al3+ atoms. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Al3+ atom.