Oxygen reduced partition function

Polynomial expressions describing oxygen reduced partition function ratios (1000 In P) for minerals where x= 10 /T (K). The equations are only applicable at temperatures above 400K. The fractionation factor between any two phases at a particular temperature is given by the algebraic difference in their 1000 Inf values (1000 In Pa - 1000 In Pb). Expressions are from Clayton and Kieffer (1991) and Chacko et al. (1996). 

Oxygen isotopic fractionation between two minerals A and B at any given T can easily be obtained by subtracting their respective reduced partition function equations—i.e.,... 

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