Materials Data on NaMn2O4 by Materials Project

Abstract

NaMn2O4 is Orthorhombic Perovskite-like structured and crystallizes in the monoclinic Pm space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.68 Å. In the second Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.28–2.68 Å. There are two inequivalent Mn+3.50+ sites. In the first Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 1–43°. There are a spread of Mn–O bond distances ranging from 1.88–2.16 Å. In the second Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form a mixture of edge and corner-sharing MnO6 octahedra. The corner-sharing octahedra tilt angles range from 1–43°. There are a spread of Mn–O bond distances ranging from 1.88–2.17 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+ and three Mn+3.50+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Na1+ and three Mn+3.50+ atoms. In the third O2- site, O2- is bonded to two equivalent Na1+ and two equivalent Mn+3.50+ atoms to form distorted ONa2Mn2 tetrahedra that share corners with two equivalent ONa2Mn2 tetrahedra and edges with four equivalent ONa2Mn4 octahedra. In the fourth O2- site, O2- is bonded to two equivalent Na1+ and two equivalent Mn+3.50+ atoms to form distorted ONa2Mn2 tetrahedra that share corners with two equivalent ONa2Mn2 tetrahedra and edges with four equivalent ONa2Mn4 octahedra. In the fifth O2- site, O2- is bonded to two Na1+ and four Mn+3.50+ atoms to form distorted ONa2Mn4 octahedra that share corners with two equivalent ONa2Mn4 octahedra, edges with two equivalent ONa2Mn4 octahedra, and edges with four ONa2Mn2 tetrahedra. The corner-sharing octahedral tilt angles are 46°.