ALKALI CARBONATES - RAMAN-SPECTROSCOPY, AB-INITIO CALCULATIONS, AND STRUCTURE

Equilibrium structures of Li2CO3 and K2CO3 were calculated using ab in itio molecular orbital calculations carried out at the Hartree-Fock (H F) level. Of the four structures considered for Li2CO3 and K2CO3, the most stable was a structure with all five atoms in a plane. The harmon ic frequencies were also calculated and found to be in agreement with the present Raman measurements. Structure factors, calculated from the ab initio data for each of the four structures considered, are compar ed with existing X-ray results.