Results for “F-Mo-Na-O” | Engineering Papers

DOE OSTI2020

Materials Data on NaMoO3F by Materials Project

NaMoO3F is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. Na1+ is bonded to three O2- and three equivalent F1- atoms to form distorted edge-sharing NaO3F3 octahedra. There are one shorter (2.41 Å) and two longer (2.55 Å) Na–O bond lengths. There are one shorter (2.35 Å) and two longer (2.36 Å) Na–F bond lengths. Mo6+ is bonded in a 6-coordinate geometry to five O2- and one F1- atom. There are a spread of Mo–O bond distances ranging from 1.73–2.39 Å. The Mo–F bond length is 2.17 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+ and one Mo6+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Na1+ and one Mo6+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent Mo6+ atoms. F1- is bonded to three equivalent Na1+ and one Mo6+ atom to form a mixture of distorted edge and corner-sharing FNa3Mo tetrahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Na3MoO4F by Materials Project

Na3MoO4F crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- and two equivalent F1- atoms to form distorted NaO4F2 octahedra that share corners with two equivalent NaO4F2 octahedra, corners with four equivalent NaO4F2 pentagonal pyramids, corners with four equivalent MoO4 tetrahedra, and faces with four equivalent NaO4F2 pentagonal pyramids. The corner-sharing octahedral tilt angles are 12°. There are a spread of Na–O bond distances ranging from 2.42–2.60 Å. There are one shorter (2.26 Å) and one longer (2.44 Å) Na–F bond lengths. In the second Na1+ site, Na1+ is bonded to four O2- and two equivalent F1- atoms to form distorted NaO4F2 pentagonal pyramids that share corners with two equivalent NaO4F2 octahedra, corners with three equivalent NaO4F2 pentagonal pyramids, corners with four equivalent MoO4 tetrahedra, edges with two equivalent NaO4F2 pentagonal pyramids, faces with two equivalent NaO4F2 octahedra, and a faceface with one NaO4F2 pentagonal pyramid. The corner-sharing octahedra tilt angles range from 71–76°. There are a spread of Na–O bond distances ranging from 2.38–2.72 Å. There are one shorter (2.31 Å) and one longer (2.37 Å) Na–F bond lengths. Mo6+ is bonded to four O2- atoms to form MoO4 tetrahedra that share corners with four equivalent NaO4F2 octahedra and corners with eight equivalent NaO4F2 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 49–67°. There are a spread of Mo–O bond distances ranging from 1.79–1.81 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one Mo6+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Na1+ and one Mo6+ atom. In the third O2- site, O2- is bonded to three Na1+ and one Mo6+ atom to form ONa3Mo tetrahedra that share corners with six equivalent FNa6 octahedra. The corner-sharing octahedra tilt angles range from 11–64°. F1- is bonded to six Na1+ atoms to form FNa6 octahedra that share corners with six equivalent ONa3Mo tetrahedra and faces with two equivalent FNa6 octahedra.

36 MATERIALS SCIENCE↗