DOE OSTI2020
Li5Ni9P7 crystallizes in the hexagonal P-6 space group. The structure is three-dimensional. there are three inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five P3- atoms to form distorted LiP5 square pyramids that share corners with four LiP6 pentagonal pyramids, corners with four equivalent LiP5 square pyramids, corners with eight NiP4 tetrahedra, an edgeedge with one LiP6 pentagonal pyramid, edges with four equivalent LiP5 square pyramids, and edges with seven NiP4 tetrahedra. There are a spread of Li–P bond distances ranging from 2.42–2.57 Å. In the second Li1+ site, Li1+ is bonded to six equivalent P3- atoms to form distorted LiP6 pentagonal pyramids that share corners with six equivalent LiP5 square pyramids, corners with twelve NiP4 tetrahedra, edges with twelve NiP4 tetrahedra, and faces with two equivalent LiP6 pentagonal pyramids. All Li–P bond lengths are 2.77 Å. In the third Li1+ site, Li1+ is bonded to six equivalent P3- atoms to form distorted LiP6 pentagonal pyramids that share corners with six equivalent LiP5 square pyramids, corners with twelve NiP4 tetrahedra, edges with three equivalent LiP5 square pyramids, edges with nine NiP4 tetrahedra, and faces with two equivalent LiP6 pentagonal pyramids. All Li–P bond lengths are 2.76 Å. There are three inequivalent Ni+1.78+ sites. In the first Ni+1.78+ site, Ni+1.78+ is bonded to four P3- atoms to form NiP4 tetrahedra that share corners with four LiP6 pentagonal pyramids, corners with two equivalent LiP5 square pyramids, corners with ten NiP4 tetrahedra, an edgeedge with one LiP6 pentagonal pyramid, edges with four equivalent LiP5 square pyramids, and edges with three NiP4 tetrahedra. There are a spread of Ni–P bond distances ranging from 2.24–2.28 Å. In the second Ni+1.78+ site, Ni+1.78+ is bonded to four P3- atoms to form NiP4 tetrahedra that share corners with two equivalent LiP6 pentagonal pyramids, corners with two equivalent LiP5 square pyramids, corners with twelve NiP4 tetrahedra, edges with three LiP6 pentagonal pyramids, edges with two equivalent LiP5 square pyramids, and edges with three NiP4 tetrahedra. There are a spread of Ni–P bond distances ranging from 2.21–2.35 Å. In the third Ni+1.78+ site, Ni+1.78+ is bonded to four P3- atoms to form NiP4 tetrahedra that share corners with two equivalent LiP6 pentagonal pyramids, corners with four equivalent LiP5 square pyramids, corners with ten NiP4 tetrahedra, edges with three LiP6 pentagonal pyramids, an edgeedge with one LiP5 square pyramid, and edges with four NiP4 tetrahedra. There are a spread of Ni–P bond distances ranging from 2.21–2.30 Å. There are three inequivalent P3- sites. In the first P3- site, P3- is bonded in a 9-coordinate geometry to three Li1+ and six Ni+1.78+ atoms. In the second P3- site, P3- is bonded in a 9-coordinate geometry to six equivalent Li1+ and three equivalent Ni+1.78+ atoms. In the third P3- site, P3- is bonded in a 9-coordinate geometry to four Li1+ and five Ni+1.78+ atoms.