The first derivative of Gibbs energy with respect to pressure is the molar volume, which contains exactly the same thermodynamic information as the density. Enthalpy is derived from first derivative of Gibbs energy with respect to temperature. However, enthalpy simply is U + P V . We observed that using H in the objective function leads to a degeneracy problem, as there are many combinations of U and P V which can lead to the same error in H. We therefore use U instead of H in our optimization function to capture the temperature derivative of Gibbs energy. Reducing deviations from experimental V res and U res reduces the error in the gradients of the Gibbs energy surface in the P and T directions, respectively. Isothermal compressibility (κ) is derived from the second derivative of Gibbs energy with respect to pressure. Similarly, isobaric heat capacity, C P is derived using the second derivative of the Gibbs energy with respect to temperature. Thus, reducing errors in C Pres and κ will minimize error in the curvature of the Gibbs energy surface in the P and T directions. We did not include mixed derivative properties, i. e. α(T, P ), as the computational cost of estimating mixed derivative becomes a bottleneck for large number of iterations during the optimization.