Materials Data on NaMn(GeO3)2 by Materials Project

Abstract

NaMn(GeO3)2 is Esseneite structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.38–2.84 Å. Mn3+ is bonded to six O2- atoms to form MnO6 octahedra that share corners with six equivalent GeO4 tetrahedra and edges with two equivalent MnO6 octahedra. There are a spread of Mn–O bond distances ranging from 1.95–2.25 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with three equivalent MnO6 octahedra and corners with two equivalent GeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 37–62°. There are a spread of Ge–O bond distances ranging from 1.75–1.80 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to one Na1+, two equivalent Mn3+, and one Ge4+ atom to form a mixture of distorted corner and edge-sharing ONaMn2Ge tetrahedra. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Na1+ and two equivalent Ge4+ atoms. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Mn3+, and one Ge4+ atom.