DOI: 10.17188/1306920
title: Materials Data on Na5CuO4 by Materials Project

description: Na5CuO4 is Ilmenite-like structured and crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. there are five inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 trigonal pyramids that share corners with two equivalent CuO4 tetrahedra, corners with eight NaO4 tetrahedra, corners with two equivalent NaO4 trigonal pyramids, an edgeedge with one CuO4 tetrahedra, edges with two NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Na–O bond distances ranging from 2.27–2.37 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent CuO4 tetrahedra, corners with four NaO4 tetrahedra, corners with six NaO4 trigonal pyramids, an edgeedge with one CuO4 tetrahedra, edges with two NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Na–O bond distances ranging from 2.29–2.51 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent CuO4 tetrahedra, corners with six NaO4 tetrahedra, corners with four NaO4 trigonal pyramids, an edgeedge with one NaO4 tetrahedra, an edgeedge with one CuO4 tetrahedra, and edges with two NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.30–2.35 Å. In the fourth Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 tetrahedra that share corners with two equivalent CuO4 tetrahedra, corners with six NaO4 tetrahedra, corners with four NaO4 trigonal pyramids, an edgeedge with one NaO4 tetrahedra, an edgeedge with one CuO4 tetrahedra, and edges with two NaO4 trigonal pyramids. There are a spread of Na–O bond distances ranging from 2.26–2.36 Å. In the fifth Na1+ site, Na1+ is bonded to four O2- atoms to form distorted NaO4 trigonal pyramids that share corners with four equivalent CuO4 tetrahedra, corners with six NaO4 tetrahedra, corners with two equivalent NaO4 trigonal pyramids, edges with three NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Na–O bond distances ranging from 2.29–2.41 Å. Cu3+ is bonded to four O2- atoms to form CuO4 tetrahedra that share corners with six NaO4 tetrahedra, corners with six NaO4 trigonal pyramids, edges with three NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Cu–O bond distances ranging from 1.90–2.01 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to five Na1+ and one Cu3+ atom to form a mixture of distorted edge and corner-sharing ONa5Cu pentagonal pyramids. The corner-sharing octahedra tilt angles range from 50–56°. In the second O2- site, O2- is bonded to five Na1+ and one Cu3+ atom to form a mixture of distorted edge and corner-sharing ONa5Cu pentagonal pyramids. The corner-sharing octahedra tilt angles range from 50–59°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Cu3+ atom. In the fourth O2- site, O2- is bonded to five Na1+ and one Cu3+ atom to form a mixture of edge and corner-sharing ONa5Cu octahedra.