Materials Data on Ca2B2O5 by Materials Project

Abstract

Ca2B2O5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing CaO6 octahedra. The corner-sharing octahedra tilt angles range from 63–74°. There are a spread of Ca–O bond distances ranging from 2.34–2.45 Å. In the second Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Ca–O bond distances ranging from 2.31–2.65 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.37 Å) and one longer (1.44 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.37 Å) and one longer (1.42 Å) B–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to three equivalent Ca2+ and one B3+ atom to form distorted corner-sharing OCa3B tetrahedra. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three equivalent Ca2+ and one B3+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one B3+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one B3+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+ and two B3+ atoms.