Materials Data on Mg2TaCuO6 by Materials Project

Abstract

Mg2TaCuO6 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.07–2.72 Å. In the second Mg2+ site, Mg2+ is bonded in a distorted rectangular see-saw-like geometry to eight O2- atoms. There are a spread of Mg–O bond distances ranging from 2.06–2.67 Å. Ta5+ is bonded to six O2- atoms to form TaO6 octahedra that share corners with two equivalent TaO6 octahedra and corners with four equivalent CuO6 octahedra. The corner-sharing octahedra tilt angles range from 41–43°. There are a spread of Ta–O bond distances ranging from 1.97–2.02 Å. Cu3+ is bonded to six O2- atoms to form CuO6 octahedra that share corners with two equivalent CuO6 octahedra and corners with four equivalent TaO6 octahedra. The corner-sharing octahedra tilt angles range from 41–45°. There are a spread of Cu–O bond distances ranging from 1.93–2.15 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to three Mg2+, one Ta5+, and one Cu3+ atom. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Mg2+, one Ta5+, and one Cu3+ atom. In the third O2- site, O2- is bonded to two Mg2+ and two equivalent Ta5+ atoms to form distorted OMg2Ta2 trigonal pyramids that share corners with two equivalent OMg2Cu2 tetrahedra and corners with two equivalent OMg2Ta2 trigonal pyramids. In the fourth O2- site, O2- is bonded to two Mg2+ and two equivalent Cu3+ atoms to form distorted OMg2Cu2 tetrahedra that share corners with two equivalent OMg2Cu2 tetrahedra and corners with two equivalent OMg2Ta2 trigonal pyramids.