Materials Data on Mg2Ta2Ni2O9 by Materials Project

Abstract

Mg2Ta2Ni2O9 is Ilmenite-derived structured and crystallizes in the trigonal P-3c1 space group. The structure is three-dimensional. Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share corners with three equivalent MgO6 octahedra, corners with three equivalent TaO6 octahedra, corners with three equivalent NiO6 octahedra, edges with three equivalent TaO6 octahedra, and a faceface with one NiO6 octahedra. The corner-sharing octahedra tilt angles range from 48–65°. There are three shorter (2.04 Å) and three longer (2.20 Å) Mg–O bond lengths. Ta5+ is bonded to six O2- atoms to form distorted TaO6 octahedra that share corners with three equivalent MgO6 octahedra, corners with six equivalent NiO6 octahedra, edges with three equivalent MgO6 octahedra, and a faceface with one TaO6 octahedra. The corner-sharing octahedra tilt angles range from 47–58°. There are three shorter (1.92 Å) and three longer (2.13 Å) Ta–O bond lengths. Ni2+ is bonded to six equivalent O2- atoms to form NiO6 octahedra that share corners with three equivalent MgO6 octahedra, corners with six equivalent TaO6 octahedra, edges with three equivalent NiO6 octahedra, and a faceface with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 47–58°. There are three shorter (2.09 Å) and three longer (2.14 Å) Ni–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Mg2+, one Ta5+, and two equivalent Ni2+ atoms to form a mixture of distorted edge and corner-sharing OMgTaNi2 trigonal pyramids. In the second O2- site, O2- is bonded to two equivalent Mg2+ and two equivalent Ta5+ atoms to form a mixture of distorted edge and corner-sharing OMg2Ta2 trigonal pyramids.