Raman spectra of high temperature carbonate melts are correlated with carbonate species modeled at 923 K using B3LYP/(6-311+G(2d,p)) density functional calculations. Species that are theoretically stable at 923 K include O2-, O-2(-), O-2(2-), CO32-, C2O62-, CO4-, CO42-, CO44-, CO52-, KCO4-, LiCO4-, KO2-, LiO2-, NaO2-, KO2, LiO2, NaO2, KCO3-, LiCO3-, and NaCO3-. Triangular, linear, and bent forms are theoretically possible for KO2- and NaO2-. Triangular and linear forms may exist for LiO2-. Linear and triangular versions are theoretically possible for LiO2- and KO2. A triangular version of NaO2 may exist. The correlation between measured and theoretical Raman spectra indicate that monovalent cations are to be included in several of the species that produce Raman spectra.