Materials Data on Na4Mn2O5 by Materials Project
Na4Mn2O5 crystallizes in the orthorhombic Fddd space group. The structure is three-dimensional. Na1+ is bonded to five O2- atoms to form distorted NaO5 trigonal bipyramids that share corners with four equivalent MnO5 square pyramids, corners with five equivalent NaO5 trigonal bipyramids, edges with three equivalent MnO5 square pyramids, and edges with five equivalent NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.29–2.47 Å. Mn3+ is bonded to five O2- atoms to form MnO5 square pyramids that share a cornercorner with one MnO5 square pyramid, corners with eight equivalent NaO5 trigonal bipyramids, edges with two equivalent MnO5 square pyramids, and edges with six equivalent NaO5 trigonal bipyramids. There are a spread of Mn–O bond distances ranging from 1.98–2.12 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Na1+ and two equivalent Mn3+ atoms to form a mixture of edge and corner-sharing ONa4Mn2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded to four equivalent Na1+ and two equivalent Mn3+ atoms to form a mixture of distorted edge and corner-sharing ONa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 17–22°. In the third O2- site, O2- is bonded to four equivalent Na1+ and two equivalent Mn3+ atoms to form a mixture of distorted edge and corner-sharing ONa4Mn2 octahedra. The corner-sharing octahedra tilt angles range from 0–22°.