Materials Data on Mn2GeSe4 by Materials Project
Mn2GeSe4 is Spinel-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to six Se2- atoms to form MnSe6 octahedra that share corners with eight MnSe6 octahedra, corners with four equivalent GeSe4 tetrahedra, edges with two equivalent MnSe6 octahedra, and an edgeedge with one GeSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 46–53°. There are a spread of Mn–Se bond distances ranging from 2.63–2.75 Å. In the second Mn2+ site, Mn2+ is bonded to six Se2- atoms to form MnSe6 octahedra that share corners with four equivalent MnSe6 octahedra, corners with two equivalent GeSe4 tetrahedra, edges with four MnSe6 octahedra, and edges with two equivalent GeSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 48–53°. There are a spread of Mn–Se bond distances ranging from 2.60–2.70 Å. Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with six MnSe6 octahedra and edges with three MnSe6 octahedra. The corner-sharing octahedra tilt angles range from 60–66°. There are two shorter (2.45 Å) and two longer (2.46 Å) Ge–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three Mn2+ and one Ge4+ atom. In the second Se2- site, Se2- is bonded in a rectangular see-saw-like geometry to three Mn2+ and one Ge4+ atom. In the third Se2- site, Se2- is bonded to three Mn2+ and one Ge4+ atom to form distorted corner-sharing SeMn3Ge tetrahedra.