Materials Data on Na2Ca2(CO3)3 by Materials Project

Na2Ca2(CO3)3 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.45–2.64 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are four shorter (2.32 Å) and two longer (2.44 Å) Na–O bond lengths. Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.43–2.59 Å. There are two inequivalent C4+ sites. In the first C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.29 Å) and two longer (1.30 Å) C–O bond length. In the second C4+ site, C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.29 Å) and one longer (1.32 Å) C–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Ca2+, and one C4+ atom. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Na1+, two equivalent Ca2+, and one C4+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Na1+, two equivalent Ca2+, and one C4+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two Na1+, two equivalent Ca2+, and one C4+ atom.