Van der Waals surface research use of a model showing the van der Waals surfaces of molecules. Related to the title concept are the ideas of a "van der Waals volume", V, and a "van der Waals surface area," abbreviated variously as A, vdWSA, VSA, and WSA. A van der Waals surface area is an abstract conception of the surface area of atoms or molecules from a mathematical estimation, either computing it from first principles or by integrating over a corresponding van der Waals volume. In simplest case, for a spherical monatomic gas, it is simply the computed surface area of a sphere of
Capillary surface and that the most stable configuration can become metastable through mechanical jarring without too much difficulty. On the other hand, a metastable surface can sometimes spontaneously achieve lower energy without any input (seemingly at least) given enough time. Boundary conditions for stress balance describe the capillary surface at the contact line: the line where a solid meets the capillary interface; also, volume constraints can serve as boundary conditions (a suspended drop, for example, has no contact line but clearly must admit a unique solution). For static surfaces, the most common contact line boundary condition is the implementation of the contact