In particular, TIP3P-FB has been optimized to accurately reproduce these observables over a wide range of thermodynamic conditions, spanning a total of 40 training points at different temperatures and pressures. Such a parallel/multi-objective parametrization has a positive effect on the transferability of the optimized model, 26 e.g., across different conditions. In contrast, OPC3 was optimized to match such observables under standard conditions (298 K and 1 bar), while simultaneously imposing a constraint on the geometry of the water molecule. Specifically, a fixed Hydrogen-Oxygen-Hydrogen angle value is imposed to ensure that the resulting linear quadrupole moment is equal to zero. This constraint is applied because the quadrupole moment is known to have minimal significance in the context of the model's overall performance and accuracy. While both models have demonstrated similar accuracy in reproducing thermodynamic properties, they do exhibit some distinct characteristics. TIP3P-FB is characterized by a larger geometry, with a distance of 0.101 nm between the Oxygen and Hydrogen sites (d OH ) and 0.164 nm between the Hydrogen sites (d HH ).