Materials Data on Na7Cu3O8 by Materials Project
Na7Cu3O8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are two shorter (2.17 Å) and two longer (2.32 Å) Na–O bond lengths. 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 2.25–2.69 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 2.32–2.55 Å. In the fourth Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.38–2.83 Å. There are two inequivalent Cu3+ sites. In the first Cu3+ site, Cu3+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.83 Å) and two longer (1.84 Å) Cu–O bond length. In the second Cu3+ site, Cu3+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.83–1.91 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 corner and edge-sharing ONa5Cu octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and two Cu3+ atoms. In the third O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and two Cu3+ atoms. In the fourth O2- site, O2- is bonded in a 6-coordinate geometry to five Na1+ and one Cu3+ atom.