Materials Data on Cr3O8 by Materials Project

Cr3O8 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two Cr3O8 sheets oriented in the (1, 0, 0) direction. there are two inequivalent Cr+5.33+ sites. In the first Cr+5.33+ site, Cr+5.33+ is bonded to six O2- atoms to form edge-sharing CrO6 octahedra. There is four shorter (1.88 Å) and two longer (1.89 Å) Cr–O bond length. In the second Cr+5.33+ site, Cr+5.33+ is bonded to six O2- atoms to form distorted edge-sharing CrO6 octahedra. There are a spread of Cr–O bond distances ranging from 1.81–2.08 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to two equivalent Cr+5.33+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three Cr+5.33+ atoms. In the third O2- site, O2- is bonded in a water-like geometry to two Cr+5.33+ atoms.