Materials Data on La3AlO6 by Materials Project

Abstract

La3AlO6 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded to seven O2- atoms to form distorted LaO7 pentagonal bipyramids that share a cornercorner with one LaO7 hexagonal pyramid, corners with four equivalent LaO7 pentagonal bipyramids, corners with three equivalent AlO4 tetrahedra, edges with three equivalent LaO7 hexagonal pyramids, edges with two equivalent LaO7 pentagonal bipyramids, an edgeedge with one AlO4 tetrahedra, and a faceface with one LaO7 pentagonal bipyramid. There are a spread of La–O bond distances ranging from 2.33–2.77 Å. In the second La3+ site, La3+ is bonded to seven O2- atoms to form distorted LaO7 hexagonal pyramids that share corners with two equivalent LaO7 pentagonal bipyramids, a cornercorner with one AlO4 tetrahedra, edges with two equivalent LaO7 hexagonal pyramids, edges with six equivalent LaO7 pentagonal bipyramids, and an edgeedge with one AlO4 tetrahedra. There are a spread of La–O bond distances ranging from 2.41–2.62 Å. Al3+ is bonded to four O2- atoms to form AlO4 tetrahedra that share a cornercorner with one LaO7 hexagonal pyramid, corners with six equivalent LaO7 pentagonal bipyramids, an edgeedge with one LaO7 hexagonal pyramid, and edges with two equivalent LaO7 pentagonal bipyramids. There is two shorter (1.79 Å) and two longer (1.81 Å) Al–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four La3+ atoms to form a mixture of edge and corner-sharing OLa4 tetrahedra. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three La3+ and one Al3+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent La3+ and one Al3+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three La3+ and one Al3+ atom.