Unsymmetrical mixing functions

The casual user has no need to explicitly call this module.

pytzer.jfuncs provides different ways to evaluate the J function that appears in the unsymmetrical mixing terms of the Pitzer model.

One of these functions must be contained within the cfdict in order to execute the pytzer.model functions.

jfunc options

.P75_eq46

Evaluates J following Pitzer (1975) Eq. (46).

.P75_eq47

Evaluates J following Pitzer (1975) Eq. (47).

.Harvie

Evaluates J following "Harvie's method", as described by Pitzer (1991), pages 124 to 125.

.numint

Uses a numerical integration method to evaluate J "exactly". Not currently autograd-able.

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References

Pitzer, K. S. (1975). Thermodynamics of electrolytes. V. effects of higher-order electrostatic terms. J. Solution Chem. 4, 249–265. doi:10.1007/BF00646562.

Pitzer, K. S. (1991). “Ion Interaction Approach: Theory and Data Correlation,” in Activity Coefficients in Electrolyte Solutions, 2nd Edition, ed. K. S. Pitzer (CRC Press, Florida, USA), 75–153.