Materials Data on K3U3Si2O13 by Materials Project

Abstract

K3U3Si2O13 crystallizes in the hexagonal P-62c space group. The structure is three-dimensional. K1+ is bonded in a 4-coordinate geometry to eleven O2- atoms. There are a spread of K–O bond distances ranging from 2.93–3.35 Å. U5+ is bonded to six O2- atoms to form UO6 octahedra that share corners with four equivalent UO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 5–36°. There are a spread of U–O bond distances ranging from 2.12–2.22 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent UO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 25°. There is three shorter (1.63 Å) and one longer (1.65 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 linear geometry to two equivalent K1+ and two equivalent U5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent K1+, one U5+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+ and two equivalent U5+ atoms.