Materials Data on Mg2BiAsO6 by Materials Project

Abstract

Mg2BiAsO6 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Mg2+ is bonded to five O2- atoms to form distorted MgO5 trigonal bipyramids that share corners with three equivalent AsO4 tetrahedra, corners with two equivalent MgO5 trigonal bipyramids, and an edgeedge with one MgO5 trigonal bipyramid. There are one shorter (1.97 Å) and four longer (2.08 Å) Mg–O bond lengths. Bi3+ is bonded in a 4-coordinate geometry to four equivalent O2- atoms. All Bi–O bond lengths are 2.25 Å. As5+ is bonded to four O2- atoms to form AsO4 tetrahedra that share corners with six equivalent MgO5 trigonal bipyramids. There is two shorter (1.70 Å) and two longer (1.73 Å) As–O bond length. 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 bent 150 degrees geometry to one Mg2+ and one As5+ atom. In the third O2- site, O2- is bonded to two equivalent Mg2+ and two equivalent Bi3+ atoms to form a mixture of distorted corner and edge-sharing OMg2Bi2 tetrahedra.