Materials Data on MnAlSiO5 by Materials Project
MnAlSiO5 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with four equivalent SiO4 tetrahedra, corners with four equivalent AlO5 trigonal bipyramids, and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.91–2.34 Å. Al3+ is bonded to five O2- atoms to form AlO5 trigonal bipyramids that share corners with four equivalent MnO6 octahedra, corners with four equivalent SiO4 tetrahedra, and an edgeedge with one AlO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 49–63°. There are a spread of Al–O bond distances ranging from 1.82–1.96 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent MnO6 octahedra and corners with four equivalent AlO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 55–73°. There are a spread of Si–O bond distances ranging from 1.64–1.67 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Al3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mn3+ and one Al3+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mn3+, one Al3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mn3+ and one Si4+ atom.