DOE OSTI2020
Li2CuSb(PO4)2 is Hausmannite-derived structured and crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with four equivalent SbO6 octahedra, corners with two equivalent PO4 tetrahedra, edges with two equivalent LiO6 octahedra, edges with two equivalent CuO6 pentagonal pyramids, and edges with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–72°. There are a spread of Li–O bond distances ranging from 2.07–2.28 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with four equivalent CuO6 pentagonal pyramids, corners with two equivalent PO4 tetrahedra, edges with two equivalent LiO6 octahedra, edges with two equivalent SbO6 octahedra, and edges with two equivalent PO4 tetrahedra. There are a spread of Li–O bond distances ranging from 2.15–2.32 Å. Cu1+ is bonded to six O2- atoms to form distorted CuO6 pentagonal pyramids that share corners with four equivalent LiO6 octahedra, corners with four equivalent SbO6 octahedra, corners with four PO4 tetrahedra, edges with two equivalent LiO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–76°. There are a spread of Cu–O bond distances ranging from 2.10–2.55 Å. Sb3+ is bonded to six O2- atoms to form distorted SbO6 octahedra that share corners with four equivalent LiO6 octahedra, corners with four equivalent CuO6 pentagonal pyramids, corners with four PO4 tetrahedra, edges with two equivalent LiO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 54–72°. There are a spread of Sb–O bond distances ranging from 2.16–2.58 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent LiO6 octahedra, corners with three equivalent SbO6 octahedra, a cornercorner with one CuO6 pentagonal pyramid, edges with two equivalent LiO6 octahedra, and an edgeedge with one CuO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 47–62°. There are a spread of P–O bond distances ranging from 1.53–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SbO6 octahedra, corners with two equivalent LiO6 octahedra, corners with three equivalent CuO6 pentagonal pyramids, an edgeedge with one SbO6 octahedra, and edges with two equivalent LiO6 octahedra. The corner-sharing octahedra tilt angles range from 54–64°. There are a spread of P–O bond distances ranging from 1.54–1.60 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+, one Sb3+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Li1+, one Cu1+, and one P5+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Cu1+, one Sb3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Li1+, one Cu1+, one Sb3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Li1+, one Sb3+, and one P5+ atom. In the sixth O2- site, O2- is bonded to two equivalent Li1+, one Cu1+, and one P5+ atom to form distorted corner-sharing OLi2CuP trigonal pyramids.