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 .