Materials Data on K2Mg(CO3)2 by Materials Project

K2Mg(CO3)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.73–3.10 Å. Mg2+ is bonded in an octahedral geometry to six O2- atoms. There are two shorter (2.12 Å) and four longer (2.13 Å) Mg–O bond lengths. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.30 Å) and one longer (1.31 Å) C–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent K1+, one Mg2+, and one C4+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to three equivalent K1+, one Mg2+, and one C4+ atom.