Possible to separate the cubic and association terms?

[cassguff]

I am using the CPA equation of state. My question: is it possible when doing the thermodynamic derivatives in teqp to return only the cubic part or only the association part if I am doing, for example, model.get_Ar01(T,rho,z)? If not, is it equivalent to make a "cubic only" psuedo-model where I set epsABi and betaABi = 0 and then run cubic_model.get_Ar01(T,rho,z) to return just the cubic part?

[ibell]

There are some subtleties with CPA. Some bits are implemented not exactly like the underlying cubic EOS. I recommend to take a look at the code:

teqp/include/teqp/models/CPA.hpp

Line 229 in 3d88748

auto alphar(const TType& T, const RhoType& rhomolar, const VecType& molefrac) const {

[ibell]

This I guess is a better link:

teqp/include/teqp/models/CPA.hpp

Line 267 in 3d88748

auto alphar(const TType& T, const RhoType& rhomolar, const VecType& molefrac) const {