Materials Data on Na4UO5 by Materials Project

Abstract

Na4UO5 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share a cornercorner with one UO6 octahedra, corners with five equivalent NaO6 octahedra, edges with three equivalent UO6 octahedra, and edges with nine equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–21°. There are a spread of Na–O bond distances ranging from 2.37–2.85 Å. U6+ is bonded to six O2- atoms to form UO6 octahedra that share corners with two equivalent UO6 octahedra, corners with four equivalent NaO6 octahedra, and edges with twelve equivalent NaO6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are four shorter (2.04 Å) and two longer (2.33 Å) U–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Na1+ and two equivalent U6+ atoms to form corner-sharing ONa4U2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded in a 6-coordinate geometry to five equivalent Na1+ and one U6+ atom.