I am using an equation of state to calculate the thermodynamical properties of a material. I have a problem which is the ideal part of the equation. Actually, I cannot be sure that the ideal contribution in my equation is the really ideal contribution, so I decided to calculate non-ideal thermodynamic properties by subtracting the nominal ideal part my equation. I want to validate the thermodynamic properties of my equation with experimental data. are the experimental data non-ideal or total(ideal+ non-ideal)????