Original: Five common thermodynamic energy potentials areAlberty (2001) p1353: Name Symbol Formula Natural variables Internal energy Helmholtz free energy Enthalpy Gibbs free energy Landau Potential (Grand potential) where T = temperature, S = entropy, p = pressure, V = volume.
Simplified: The four most common thermodynamic potentials are: Name Formula Natural variables Internal energy Helmholtz free energy Enthalpy Gibbs free energy where T = temperature, S = entropy, p = pressure, V = volume.