Materials Data on NbSi4O13 by Materials Project
(Nb(SiO3)4)2O2 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional and consists of two water molecules and one Nb(SiO3)4 framework. In the Nb(SiO3)4 framework, Nb is bonded to six O atoms to form distorted NbO6 octahedra that share corners with five SiO4 tetrahedra. There are a spread of Nb–O bond distances ranging from 1.92–2.10 Å. There are three inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.65 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one NbO6 octahedra and corners with three SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 18°. There is two shorter (1.62 Å) and two longer (1.63 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two equivalent NbO6 octahedra and corners with two SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 24–30°. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. There are eight inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one Nb and one Si atom. In the second O site, O is bonded in a bent 150 degrees geometry to one Nb and one Si atom. In the third O site, O is bonded in a single-bond geometry to one Nb atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Nb and one Si atom. In the fifth O site, O is bonded in a single-bond geometry to one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eighth O site, O is bonded in a bent 150 degrees geometry to two Si atoms.