Materials Data on La4CoO8 by Materials Project

Abstract

La4CoO8 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. there are two inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of La–O bond distances ranging from 2.52–2.75 Å. In the second La3+ site, La3+ is bonded in a 1-coordinate geometry to nine O2- atoms. There are a spread of La–O bond distances ranging from 2.26–2.73 Å. Co4+ is bonded in an octahedral geometry to six O2- atoms. There is four shorter (1.83 Å) and two longer (2.07 Å) Co–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four La3+ and one Co4+ atom to form distorted OLa4Co square pyramids that share corners with six equivalent OLa5Co octahedra, a cornercorner with one OLa4Co square pyramid, edges with four equivalent OLa4Co square pyramids, faces with two equivalent OLa5Co octahedra, and faces with two equivalent OLa4Co square pyramids. The corner-sharing octahedra tilt angles range from 48–53°. In the second O2- site, O2- is bonded in a 5-coordinate geometry to five La3+ atoms. In the third O2- site, O2- is bonded to five La3+ and one Co4+ atom to form distorted OLa5Co octahedra that share corners with five equivalent OLa5Co octahedra, corners with twelve equivalent OLa4Co square pyramids, edges with two equivalent OLa5Co octahedra, and faces with four equivalent OLa4Co square pyramids. The corner-sharing octahedra tilt angles range from 0–17°.