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Hello,

undoubtedly I am not the only one using VASP for strain calculations, as there are many papers on the subject.
However, it is nowhere to be found explicitly whether VASP calculates the total Gibbs free energy, including enthalpy, or not. This is very important in structures under strain, and looking at papers, some have assumed they have to take enthalpy into account separately, while others assume VASP includes it automatically. Which ones are correct, and why is it not said explicitly anywhere what terms are included in the VASP total energy, besides internal energy?

VASP calculates the internal energy (U) and the free energy (F=U-TS).
please note that only the electronic entropy is taken into account in F.

VASP does calculate the stresses on the unit cell. Do you mean that it does not calculate the Gibbs free energy due to these stresses, if they are nonzero?

This would mean strain calculations have to explicitly include the PV term, which very few papers have done. Entropy does not enter into it, because I am doing 0 T calculations.