Materials Data on Na2CuO2 by Materials Project
Na2CuO2 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two 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 2.34–2.57 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form distorted corner-sharing NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.31–2.38 Å. Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.97 Å) and two longer (2.00 Å) Cu–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 7-coordinate geometry to five Na1+ and two equivalent Cu2+ atoms. In the second O2- site, O2- is bonded to four Na1+ and two equivalent Cu2+ atoms to form a mixture of corner and edge-sharing ONa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 56°.