Theoretical consideration of the solid/liquid interfacial energy for molecular crystals

Based on the previously proposed solid/liquid interfacial energy gamma sl model for metallic crystals, we extend it to describe molecular crystals. The prediction is in good agreement with other theoretical and experimental results. The temperature-dependent function gamma sl(T) is also considered, we found that gamma sl(T) increases with the increase of temperature T, and the smaller gamma sl value is, the more stable the interface is, and the weaker the temperature influence on it. Material constant k is determined to be about 0.521. It is found that when the ratio of molar melting enthalpy Hm and molecular diameter h product to molar volume Vm is greater than 45 mJ m-2, the gamma sl and Hmh/Vm fitting data points are dispersed, indicating that the k value of molecular crystals is not a strict constant, and the influence of evaporation entropy Sb on gamma sl cannot be ignored. Our work contributes to a better under-standing of the surface phenomena and physical origins of molecular crystals.