Materials Data on NaMn2O4 by Materials Project

Abstract

NaMn2O4 is Spinel-like structured and crystallizes in the orthorhombic C222_1 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with twelve MnO6 octahedra. The corner-sharing octahedra tilt angles range from 58–67°. There are two shorter (2.17 Å) and two longer (2.18 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with twelve MnO6 octahedra. The corner-sharing octahedra tilt angles range from 50–72°. There are two shorter (2.18 Å) and two longer (2.22 Å) Na–O bond lengths. 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 distorted MnO6 octahedra that share corners with six NaO4 tetrahedra and edges with six MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.95–2.31 Å. In the second Mn+3.50+ site, Mn+3.50+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six NaO4 tetrahedra and edges with six MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.91–1.99 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to one Na1+ and three Mn+3.50+ atoms to form a mixture of edge and corner-sharing ONaMn3 tetrahedra. In the second O2- site, O2- is bonded to one Na1+ and three Mn+3.50+ atoms to form a mixture of distorted edge and corner-sharing ONaMn3 trigonal pyramids. In the third O2- site, O2- is bonded to one Na1+ and three Mn+3.50+ atoms to form a mixture of distorted edge and corner-sharing ONaMn3 tetrahedra. In the fourth O2- site, O2- is bonded to one Na1+ and three Mn+3.50+ atoms to form a mixture of edge and corner-sharing ONaMn3 tetrahedra.