Materials Data on Ba2C4O9 by Materials Project
(BaC2O4)4O2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional and consists of one hydrogen peroxide molecule and one BaC2O4 framework. In the BaC2O4 framework, there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ba–O bond distances ranging from 2.78–2.95 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.76–3.30 Å. There are four inequivalent C+3.50+ sites. In the first C+3.50+ site, C+3.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.26 Å) and one longer (1.28 Å) C–O bond length. In the second C+3.50+ site, C+3.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.27 Å. In the third C+3.50+ site, C+3.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.27 Å. In the fourth C+3.50+ site, C+3.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.26 Å) and one longer (1.28 Å) C–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one C+3.50+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one C+3.50+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one C+3.50+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one C+3.50+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two Ba2+ and one C+3.50+ atom. In the sixth O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one C+3.50+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one C+3.50+ atom. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ba2+ and one C+3.50+ atom.