DOE OSTI2020
CH2O crystallizes in the orthorhombic Pbcn space group. The structure is zero-dimensional and consists of four 1,3,5,7,9-pentaoxecane molecules. there are three inequivalent C2+ sites. In the first C2+ site, C2+ is bonded to two equivalent H and two equivalent O2- atoms to form corner-sharing CH2O2 tetrahedra. Both C–H bond lengths are 1.10 Å. Both C–O bond lengths are 1.42 Å. In the second C2+ site, C2+ is bonded to two H and two O2- atoms to form corner-sharing CH2O2 tetrahedra. Both C–H bond lengths are 1.10 Å. There is one shorter (1.41 Å) and one longer (1.43 Å) C–O bond length. In the third C2+ site, C2+ is bonded to two H and two O2- atoms to form corner-sharing CH2O2 tetrahedra. Both C–H bond lengths are 1.10 Å. There is one shorter (1.42 Å) and one longer (1.43 Å) C–O bond length. There are five inequivalent H sites. In the first H site, H is bonded in a single-bond geometry to one C2+ atom. In the second H site, H is bonded in a single-bond geometry to one C2+ atom. In the third H site, H is bonded in a single-bond geometry to one C2+ atom. In the fourth H site, H is bonded in a single-bond geometry to one C2+ atom. In the fifth H site, H is bonded in a single-bond geometry to one C2+ atom. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent C2+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to two C2+ atoms. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to two C2+ atoms.