Theoretical estimation of the equilibrium distribution of clumped isotopes in nature

Using the method proposed, the equilibrium Δ47 of CO2 is found to be roughly independent of δ13C and δ18O for most geologic samples, suggesting the effects of bulk isotope compositions on Δ47 are negligible. We find that the sum of Δi for all of the singly substituted isotopologues will be equal to zero approximately, enabling us to determine the stochastic concentrations of isotopologues from experiments.