Materials Data on Mg2As2O7 by Materials Project
Mg2As2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form distorted MgO6 pentagonal pyramids that share corners with six equivalent AsO4 tetrahedra and edges with three equivalent MgO6 pentagonal pyramids. There are a spread of Mg–O bond distances ranging from 2.08–2.23 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with six equivalent MgO6 pentagonal pyramids and a cornercorner with one AsO4 tetrahedra. There are a spread of As–O bond distances ranging from 1.70–1.74 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one As5+ atom. In the second O2- site, O2- is bonded in a linear geometry to two equivalent As5+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Mg2+ and one As5+ atom.