Materials Data on Ca(CO2)2 by Materials Project

Abstract

CaC2O4 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Ca2+ is bonded to seven O2- atoms to form distorted edge-sharing CaO7 pentagonal bipyramids. There are a spread of Ca–O bond distances ranging from 2.32–2.70 Å. There are two inequivalent C3+ sites. In the first C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.25 Å. In the second C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.26 Å) C–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ca2+ and one C3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ca2+ and one C3+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+ and one C3+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+ and one C3+ atom.