Materials Data on Na2CaC2O3 by Materials Project

Na2CaCO3C crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of four methane molecules and two Na2CaCO3 sheets oriented in the (0, 0, 1) direction. In each Na2CaCO3 sheet, Na1+ is bonded in a 3-coordinate geometry to three O2- atoms. There are one shorter (2.35 Å) and two longer (2.43 Å) Na–O bond lengths. Ca2+ is bonded in a hexagonal planar geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.55–2.59 Å. C1+ is bonded in a trigonal planar geometry to three O2- atoms. All C–O bond lengths are 1.30 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Na1+, two equivalent Ca2+, and one C1+ atom. In the second O2- site, O2- is bonded to two equivalent Na1+, two equivalent Ca2+, and one C1+ atom to form distorted corner-sharing ONa2Ca2C trigonal bipyramids.