Materials Data on CaSi2NiO6 by Materials Project

Abstract

CaNiSi2O6 is Esseneite structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.34–2.76 Å. Ni2+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with two equivalent NiO6 octahedra. There are a spread of Ni–O bond distances ranging from 2.07–2.14 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent NiO6 octahedra and corners with two equivalent SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 35–59°. There are a spread of Si–O bond distances ranging from 1.60–1.70 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ca2+ and two equivalent Si4+ atoms. In the second O2- site, O2- is bonded in a distorted T-shaped geometry to one Ca2+, one Ni2+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to one Ca2+, two equivalent Ni2+, and one Si4+ atom.