Materials Data on LiCaAlN2 by Materials Project

Abstract

LiCaAlN2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Li1+ is bonded to four N3- atoms to form distorted LiN4 tetrahedra that share corners with six equivalent CaN6 octahedra, corners with two equivalent LiN4 tetrahedra, corners with four equivalent AlN4 tetrahedra, edges with three equivalent CaN6 octahedra, an edgeedge with one LiN4 tetrahedra, and edges with two equivalent AlN4 tetrahedra. The corner-sharing octahedra tilt angles range from 26–63°. There are a spread of Li–N bond distances ranging from 2.05–2.28 Å. Ca2+ is bonded to six N3- atoms to form distorted CaN6 octahedra that share corners with six equivalent LiN4 tetrahedra, corners with six equivalent AlN4 tetrahedra, edges with six equivalent CaN6 octahedra, edges with three equivalent LiN4 tetrahedra, and edges with three equivalent AlN4 tetrahedra. There are a spread of Ca–N bond distances ranging from 2.42–2.69 Å. Al3+ is bonded to four N3- atoms to form AlN4 tetrahedra that share corners with six equivalent CaN6 octahedra, corners with two equivalent AlN4 tetrahedra, corners with four equivalent LiN4 tetrahedra, edges with three equivalent CaN6 octahedra, an edgeedge with one AlN4 tetrahedra, and edges with two equivalent LiN4 tetrahedra. The corner-sharing octahedra tilt angles range from 19–61°. There are a spread of Al–N bond distances ranging from 1.92–1.97 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded in a 7-coordinate geometry to two equivalent Li1+, three equivalent Ca2+, and two equivalent Al3+ atoms. In the second N3- site, N3- is bonded in a 7-coordinate geometry to two equivalent Li1+, three equivalent Ca2+, and two equivalent Al3+ atoms.