The reweighting involves re-evaluating energies using the simulated trajectories for (22 (T)× 6 (F)) 2 × 1 (P) = 17,424 states. As there are 21 different pressures, we need to calculate the energy at (22(T)×6(F)) 2 ×21(P) = 365,904 states. Property estimation requires estimation of Gibbs energy differences corresponding to (22(T) × 6(F)) 2 × 21(P) × 5 states = 1,829,520 states because at each temperature and pressure, we need four more states corresponding to (β,P + δP ),(β,P -δP ), (β +δβ,P ), (β -δβ,P ) to numerically estimate the first and second derivatives of the reduced Gibbs energy with respect to temperature and pressure. Only changes in the model require mapping and/or reevaluation, as only temperature and pressure changes are made for many of the states.