Materials Data on Na3VH6O7 by Materials Project
Na3VH6O7 crystallizes in the trigonal R3 space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with three equivalent VO4 tetrahedra, and edges with four equivalent NaO6 octahedra. The corner-sharing octahedral tilt angles are 16°. There are a spread of Na–O bond distances ranging from 2.33–2.65 Å. V5+ is bonded to four O2- atoms to form VO4 tetrahedra that share corners with nine equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. There is one shorter (1.73 Å) and three longer (1.76 Å) V–O bond length. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.72 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a single-bond geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.79 Å) H–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to three equivalent Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Na1+ and one V5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+, one V5+, and two H1+ atoms.