Materials Data on CoB4O7 by Materials Project
Co(B4O7) crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Co2+ is bonded to five O2- atoms to form distorted CoO5 trigonal bipyramids that share corners with ten BO4 tetrahedra. There are four shorter (2.06 Å) and one longer (2.09 Å) Co–O bond lengths. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share corners with six BO4 tetrahedra and corners with two equivalent CoO5 trigonal bipyramids. There is two shorter (1.45 Å) and two longer (1.56 Å) B–O bond length. In the second B3+ site, B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share corners with five BO4 tetrahedra and corners with three equivalent CoO5 trigonal bipyramids. There are a spread of B–O bond distances ranging from 1.44–1.57 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Co2+ and two equivalent B3+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three B3+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Co2+ and two B3+ atoms.