Intermolecular interactions constitute one of the major forces determining numerous specific properties and self organization of condensed matter including biological systems. There is no better illustration of their importance than the introduction in the famous textbook The Feynman Lectures on Physics: If, in some cataclysm, all of scientific knowledge were to be destroyed, and only one sentence passed on to the next generations of creatures, what statement would contain the most information in the fewest words? I believe it is the atomic hypothesis that all things are made of atoms – little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. This statement refers directly to the concept of the potential energy function describing interaction energy as a function of the distance sufficient to model various properties of matter that are directly or indirectly related to the intermolecular forces. Recent progress in computational and experimental techniques opens the perspective for rational de novo design of new materials with desired properties being governed by specific interactions.