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
Surface energy number of atoms at the surface and in the bulk of the solid. Calculating the surface formation energy of a crystalline solid In density functional theory, surface energy can be calculated from the following expression where formula_17 is the total energy of surface slab obtained using density functional theory. formula_18 is the number of atoms in the surface slab. formula_19 is the bulk energy per atom. formula_6 is the surface area. For a slab, we have two surfaces and they are of the same type, which is reflected by the number 2 in the denominator. To guarantee this, we need