Materials Data on La2Ni2O5 by Materials Project

Abstract

La2Ni2O5 crystallizes in the orthorhombic Ima2 space group. The structure is three-dimensional. La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.40–2.92 Å. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent NiO6 octahedra and corners with two equivalent NiO4 tetrahedra. The corner-sharing octahedral tilt angles are 13°. There are four shorter (1.99 Å) and two longer (2.21 Å) Ni–O bond lengths. In the second Ni2+ site, Ni2+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with two equivalent NiO6 octahedra and corners with two equivalent NiO4 tetrahedra. The corner-sharing octahedral tilt angles are 35°. There are a spread of Ni–O bond distances ranging from 1.95–2.04 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four equivalent La3+ and two equivalent Ni2+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three equivalent La3+ and two Ni2+ atoms. In the third O2- site, O2- is bonded to two equivalent La3+ and two equivalent Ni2+ atoms to form distorted corner-sharing OLa2Ni2 tetrahedra.