Materials Data on K3Nb3Si2O13 by Materials Project

Abstract

K3Nb3Si2O13 crystallizes in the hexagonal P-62c space group. The structure is three-dimensional. K1+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of K–O bond distances ranging from 2.88–3.32 Å. Nb5+ is bonded to six O2- atoms to form NbO6 octahedra that share corners with four equivalent NbO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 9–30°. There are a spread of Nb–O bond distances ranging from 1.98–2.07 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent NbO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 24°. There is three shorter (1.63 Å) and one longer (1.64 Å) Si–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to three equivalent K1+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent K1+, one Nb5+, and one Si4+ atom. In the third O2- site, O2- is bonded in a linear geometry to three equivalent K1+ and two equivalent Nb5+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent K1+ and two equivalent Nb5+ atoms.