Materials Data on K4H6C2O9 by Materials Project

K4C2H6O9 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 8-coordinate geometry to two equivalent H1+ and six O2- atoms. Both K–H bond lengths are 2.76 Å. There are a spread of K–O bond distances ranging from 2.78–2.83 Å. In the second K1+ site, K1+ is bonded in a 10-coordinate geometry to two equivalent H1+ and eight O2- atoms. Both K–H bond lengths are 2.85 Å. There are a spread of K–O bond distances ranging from 2.78–3.14 Å. In the third K1+ site, K1+ is bonded in a 10-coordinate geometry to two H1+ and eight O2- atoms. There are one shorter (2.79 Å) and one longer (2.97 Å) K–H bond lengths. There are a spread of K–O bond distances ranging from 2.82–3.22 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.29 Å) and two longer (1.31 Å) C–O bond length. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to one K1+ and one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one K1+ and one O2- atom. The H–O bond length is 1.00 Å. In the third H1+ site, H1+ is bonded in a distorted single-bond geometry to two K1+ and one O2- atom. The H–O bond length is 1.01 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to five K1+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to four K1+ and one C4+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one C4+ atom. In the fourth O2- site, O2- is bonded in a water-like geometry to two equivalent K1+ and two equivalent H1+ atoms. In the fifth O2- site, O2- is bonded in a water-like geometry to three K1+ and two H1+ atoms.