Materials Data on SiPHO5 by Materials Project
SiPO4(OH) crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Si4+ is bonded to six O2- atoms to form SiO6 octahedra that share corners with two equivalent SiO6 octahedra and corners with four equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. There are a spread of Si–O bond distances ranging from 1.74–1.84 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent SiO6 octahedra. The corner-sharing octahedra tilt angles range from 38–40°. All P–O bond lengths are 1.54 Å. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Si4+ and one H1+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Si4+ and one P5+ atom.