Atomistic computing of the solid–fluid surface free energy and tension

This Review surveys methods that use atomistic simulations to compute solid–fluid surface tension, a key parameter for understanding and controlling physical properties at interfaces. Accurate calculation and understanding of these properties are increasingly important in applications, especially in confined-fluid systems in which surface effects dominate over bulk properties. Traditional approaches such as contact angle measurements, the Wilhelmy plate method, and sessile drop methods often fall short in directly measuring solid–liquid surface tension. By contrast, molecular simulations allow the direct extraction of this parameter, offering a more detailed insight into its behaviour at the nanoscale. The Review emphasizes the challenges associated with solid–fluid interfaces, particularly their anisotropic nature, and discusses computational techniques such as the cleaving method, perturbation approaches and capillary wave theory. This article reviews atomistic methods for computing solid–fluid surface free energy and tension, highlighting challenges from anisotropy. It discusses simulation techniques and methodological developments, and emphasizes the need for improved methods to address complex, confined or disordered systems.