Materials Data on CsNb2(SiO3)8 by Materials Project
CsNb2(SiO3)8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Cs is bonded in a 10-coordinate geometry to ten O atoms. There are a spread of Cs–O bond distances ranging from 3.29–3.67 Å. 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 1.92–2.09 Å. There are four inequivalent Si sites. In the first 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 19°. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. In the second 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 26–29°. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. 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 27–34°. There is two shorter (1.63 Å) and two longer (1.64 Å) Si–O bond length. In the fourth 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. There are twelve inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Cs and one Si atom. In the second O site, O is bonded in a single-bond geometry to one Nb atom. In the third O site, O is bonded in a bent 150 degrees geometry to one Nb and one Si atom. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to one Cs, one Nb, and one Si atom. In the fifth O site, O is bonded in a distorted bent 150 degrees geometry to one Cs, one Nb, and one Si atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Cs and 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 one Cs and two Si atoms. In the ninth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the tenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a bent 150 degrees geometry to one Nb and one Si atom. In the twelfth O site, O is bonded in a bent 150 degrees geometry to one Nb and one Si atom.