Materials Data on Na6P2H2O9 by Materials Project
Na6P2H2O9 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.29–2.74 Å. In the second Na1+ site, Na1+ is bonded in a 7-coordinate geometry to one H1+ and six O2- atoms. The Na–H bond length is 2.54 Å. There are a spread of Na–O bond distances ranging from 2.40–2.84 Å. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with two equivalent NaO6 octahedra, corners with three equivalent PO4 tetrahedra, an edgeedge with one PO4 tetrahedra, and a faceface with one NaO6 octahedra. The corner-sharing octahedral tilt angles are 78°. There are a spread of Na–O bond distances ranging from 2.35–2.51 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent NaO6 octahedra and an edgeedge with one NaO6 octahedra. The corner-sharing octahedra tilt angles range from 30–69°. There is three shorter (1.56 Å) and one longer (1.57 Å) P–O bond length. H1+ is bonded in a single-bond geometry to one Na1+ and one O2- atom. The H–O bond length is 1.00 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to four Na1+ and two equivalent H1+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to four Na1+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to four Na1+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Na1+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one P5+ atom.