Materials Data on MnAlO3 by Materials Project

Abstract

MnAlO3 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Mn3+ is bonded to six O2- atoms to form distorted MnO6 octahedra that share corners with six equivalent MnO6 octahedra and corners with eight equivalent AlO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 55–56°. There are a spread of Mn–O bond distances ranging from 1.93–2.35 Å. Al3+ is bonded to four O2- atoms to form distorted AlO4 trigonal pyramids that share corners with eight equivalent MnO6 octahedra and corners with two equivalent AlO4 trigonal pyramids. The corner-sharing octahedra tilt angles range from 62–83°. All Al–O bond lengths are 1.81 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Mn3+ and one Al3+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Mn3+ and two equivalent Al3+ atoms.