Materials Data on CrO2 by Materials Project

Abstract

CrO2 crystallizes in the trigonal R3m space group. The structure is three-dimensional. there are two inequivalent Cr4+ sites. In the first Cr4+ site, Cr4+ is bonded to four O2- atoms to form corner-sharing CrO4 tetrahedra. The corner-sharing octahedra tilt angles range from 56–59°. There is three shorter (1.82 Å) and one longer (1.88 Å) Cr–O bond length. In the second Cr4+ site, Cr4+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with three equivalent CrO4 tetrahedra and edges with four equivalent CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.84–2.09 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three Cr4+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal pyramidal geometry to four Cr4+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to three equivalent Cr4+ atoms. In the fourth O2- site, O2- is bonded in a water-like geometry to two equivalent Cr4+ atoms.