Materials Data on NaNbGeO5 by Materials Project
NaNbGeO5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.36–2.59 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with two equivalent NbO6 octahedra and corners with four equivalent GeO4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Nb–O bond distances ranging from 1.83–2.23 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four equivalent NbO6 octahedra. The corner-sharing octahedra tilt angles range from 32–56°. There is three shorter (1.77 Å) and one longer (1.78 Å) Ge–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to two equivalent Na1+, one Nb5+, and one Ge4+ atom to form distorted edge-sharing ONa2NbGe tetrahedra. In the second O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one Ge4+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+ and two equivalent Nb5+ atoms. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Nb5+, and one Ge4+ atom.