Materials Data on Na4UC3O11 by Materials Project

Abstract

Na4UC3O11 crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.54 Å. In the second Na1+ site, Na1+ is bonded to six equivalent O2- atoms to form face-sharing NaO6 octahedra. All Na–O bond lengths are 2.49 Å. In the third Na1+ site, Na1+ is bonded to six equivalent O2- atoms to form distorted face-sharing NaO6 pentagonal pyramids. All Na–O bond lengths are 2.53 Å. U6+ is bonded in a distorted hexagonal bipyramidal geometry to eight O2- atoms. There are a spread of U–O bond distances ranging from 1.86–2.44 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.27–1.32 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one U6+, and one C4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Na1+ and one U6+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three equivalent Na1+ and one U6+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Na1+, one U6+, and one C4+ atom. In the fifth O2- site, O2- is bonded to three Na1+ and one C4+ atom to form a mixture of distorted edge and corner-sharing ONa3C tetrahedra.