Materials Data on Na2H6C4O7 by Materials Project

Na2C2H6O5(CO)2 crystallizes in the monoclinic C2/c space group. The structure is two-dimensional and consists of eight formaldehyde molecules and two Na2C2H6O5 sheets oriented in the (0, 0, 1) direction. In each Na2C2H6O5 sheet, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.63 Å. C+1.50+ is bonded in a single-bond geometry to one O2- atom. The C–O bond length is 1.27 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three equivalent Na1+ and one C+1.50+ atom. In the second O2- site, O2- is bonded in a water-like geometry to two equivalent Na1+ and two equivalent H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms.