DOE OSTI2020
MnCo3(PO4)4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Mn2+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with four equivalent CoO6 pentagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. There are a spread of Mn–O bond distances ranging from 1.90–2.31 Å. There are three inequivalent Co+3.33+ sites. In the first Co+3.33+ site, Co+3.33+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with four equivalent CoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are two shorter (1.89 Å) and four longer (2.11 Å) Co–O bond lengths. In the second Co+3.33+ site, Co+3.33+ is bonded to six O2- atoms to form distorted CoO6 pentagonal pyramids that share corners with four equivalent MnO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. There are a spread of Co–O bond distances ranging from 1.88–2.30 Å. In the third Co+3.33+ site, Co+3.33+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share corners with four equivalent CoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–49°. There are a spread of Co–O bond distances ranging from 1.88–2.11 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one MnO6 octahedra, corners with three CoO6 octahedra, and an edgeedge with one CoO6 octahedra. The corner-sharing octahedra tilt angles range from 43–57°. There is two shorter (1.54 Å) and two longer (1.56 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one MnO6 octahedra, a cornercorner with one CoO6 octahedra, corners with two equivalent CoO6 pentagonal pyramids, and an edgeedge with one MnO6 octahedra. The corner-sharing octahedra tilt angles range from 39–52°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three CoO6 octahedra, a cornercorner with one CoO6 pentagonal pyramid, and an edgeedge with one CoO6 octahedra. The corner-sharing octahedra tilt angles range from 43–57°. There is two shorter (1.54 Å) and two longer (1.57 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with two equivalent MnO6 octahedra, a cornercorner with one CoO6 pentagonal pyramid, and an edgeedge with one CoO6 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 36–54°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to two Co+3.33+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Co+3.33+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Co+3.33+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Co+3.33+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Co+3.33+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Co+3.33+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Co+3.33+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to one Mn2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Co+3.33+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one Mn2+, one Co+3.33+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to one Co+3.33+ and one P5+ atom.