“…26 The carbon atom, C(20), and three surrounding oxygen atoms of the carbonate group are planar, with deviations from the least-squares plane of 0.001 Á. The angles around C (20) vary from 106.9°to 127.2°even though the suni is 360°. This represents a considerable distortion from the normal 120°in the carbonate ion.27 Inorganic Carbonates show some variations from 120°, but not as large as these.…”