Ice−Water Interfacial Free Energy for the TIP4P, TIP4P/2005, TIP4P/ Ice, and mW Models As Obtained from the Mold Integration Technique

The freezing of water is greatly influenced by the ice−water interfacial free energy. Yet, no consistent experimental measures of this thermodynamic parameter can be found. In this work we provide estimates for the ice Ih− water interfacial free energy at the normal melting temperature for different crystal planes (basal, primary prismatic, and secondary prismatic) using some widely used water models: TIP4P, TIP4P/2005, TIP4P/Ice, and mW. To compute the interfacial free energy, we use the mold integration method. It consists in calculating the work needed to induce the formation of a crystal slab in the fluid at coexistence conditions with the aid of a mold of potential energy wells whose structure is that of the crystal plane under study. The basal plane has the lowest interfacial free energy in all models of the TIP4P family. For the mW model we could not resolve differences in interfacial free energy between different orientations. The interfacial free energies averaged over all crystal orientations we obtain are 27.2(8), 28.9(8), 29.8(8), and 34.9(8) mJ/m for the TIP4P, TIP4P/2005, TIP4P/Ice, and mW models, respectively. The averaged interfacial free energy increases with both the melting temperature and melting enthalpy of the model. Moreover, we compute the interfacial free energy for several crystal orientation of ice Ic using the TIP4P/Ice model and obtain within the accuracy of our calculations the same orientationally averaged interfacial free energy as that of ice Ih. Our results are in good agreement with previous estimates of the interfacial free energy based on a classical nucleation theory analysis of simulations of spherical ice seeds embedded in supercooled water.