DOE OSTI2020
Co4(MoO4)3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Mo+5.33+ sites. In the first Mo+5.33+ site, Mo+5.33+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with eight CoO6 octahedra. The corner-sharing octahedra tilt angles range from 30–66°. There are a spread of Mo–O bond distances ranging from 1.83–1.90 Å. In the second Mo+5.33+ site, Mo+5.33+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with five CoO6 octahedra and corners with three equivalent CoO6 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 27–62°. There are a spread of Mo–O bond distances ranging from 1.80–1.85 Å. There are three inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with six MoO4 tetrahedra and faces with two equivalent CoO6 octahedra. There are a spread of Co–O bond distances ranging from 2.07–2.10 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form distorted CoO6 pentagonal pyramids that share corners with two equivalent CoO6 octahedra, corners with six equivalent MoO4 tetrahedra, and edges with two equivalent CoO6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 62°. There are a spread of Co–O bond distances ranging from 2.09–2.21 Å. In the third Co2+ site, Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share a cornercorner with one CoO6 octahedra, a cornercorner with one CoO6 pentagonal pyramid, corners with six MoO4 tetrahedra, and edges with two equivalent CoO6 octahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Co–O bond distances ranging from 2.06–2.13 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mo+5.33+ and two equivalent Co2+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to one Mo+5.33+ and two Co2+ atoms. In the third O2- site, O2- is bonded in a trigonal planar geometry to one Mo+5.33+ and two equivalent Co2+ atoms. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mo+5.33+ and two equivalent Co2+ atoms. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mo+5.33+ and two equivalent Co2+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Mo+5.33+ and two equivalent Co2+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mo+5.33+ and two equivalent Co2+ atoms.