Materials Data on NaGe2(PO4)3 by Materials Project

Abstract

NaGe2P3O12 crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted hexagonal planar geometry to six equivalent O2- atoms. All Na–O bond lengths are 2.42 Å. In the second Na1+ site, Na1+ is bonded in a hexagonal planar geometry to six equivalent O2- atoms. All Na–O bond lengths are 2.54 Å. There are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There is three shorter (1.88 Å) and three longer (1.92 Å) Ge–O bond length. In the second Ge4+ site, Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There is three shorter (1.87 Å) and three longer (1.91 Å) Ge–O bond length. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four GeO6 octahedra. The corner-sharing octahedra tilt angles range from 29–40°. There are a spread of P–O bond distances ranging from 1.53–1.55 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Ge4+, and one P5+ atom. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Ge4+, and one P5+ atom. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to one Ge4+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ge4+ and one P5+ atom.