Materials Data on Ca(BO2)2 by Materials Project

CaB2O4 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.41–2.61 Å. In the second Ca2+ site, Ca2+ is bonded to twelve O2- atoms to form CaO12 cuboctahedra that share corners with twelve equivalent BO4 tetrahedra and edges with six equivalent BO4 tetrahedra. There are six shorter (2.70 Å) and six longer (2.82 Å) Ca–O bond lengths. B3+ is bonded to four O2- atoms to form BO4 tetrahedra that share corners with two equivalent CaO12 cuboctahedra, corners with four equivalent BO4 tetrahedra, and an edgeedge with one CaO12 cuboctahedra. There are a spread of B–O bond distances ranging from 1.47–1.50 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Ca2+ and two equivalent B3+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to three Ca2+ and two equivalent B3+ atoms.