Materials Data on Na3(CuO2)2 by Materials Project

Abstract

Na3Cu2O4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 4-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.94 Å. In the second 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 2.29–2.68 Å. In the third Na1+ site, Na1+ is bonded to five O2- atoms to form distorted edge-sharing NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.33–2.44 Å. There are two inequivalent Cu+2.50+ sites. In the first Cu+2.50+ site, Cu+2.50+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.87–1.91 Å. In the second Cu+2.50+ site, Cu+2.50+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.90–1.92 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to three Na1+ and two Cu+2.50+ atoms to form a mixture of distorted corner and edge-sharing ONa3Cu2 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 5–50°. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and two Cu+2.50+ atoms. In the third O2- site, O2- is bonded to four Na1+ and two Cu+2.50+ atoms to form distorted ONa4Cu2 trigonal bipyramids that share a cornercorner with one ONa4Cu2 octahedra, corners with two equivalent ONa4Cu2 trigonal bipyramids, edges with three equivalent ONa4Cu2 octahedra, and edges with three equivalent ONa3Cu2 trigonal bipyramids. The corner-sharing octahedral tilt angles are 1°. In the fourth O2- site, O2- is bonded to four Na1+ and two Cu+2.50+ atoms to form a mixture of distorted corner and edge-sharing ONa4Cu2 octahedra.