In this chapter we have presented a review of direct measurement of interparticle force-distance relationship from which intermolecular potential energy functions data can be generated along with the methodology in using quantum mechanical ab initio calculation for generation of interparticle potential energy data. We have also presented a set of state-of-the-art phenomenological interatomic and intermolecular potential energy functions that are widely used in computational modeling at the nanoscale when several hundred to several millions of particles are involved. There is still a great deal of work need to be done in order to develop a thorough database for interatomic and intermolecular potential energy functions to be sufficient for applications in nanoscience and nanotechnology. Since to control the matter atom by atom, molecule by molecule and/or at the macromolecular level, which is the aim of the nanotechnology, it is necessary to know the exact intermolecular forces between the particles under consideration. In the development of intermolecular force models applicable for the study of nanostructures which are at the confluence of the smallest of human-made devices and the largest molecules of living systems it is necessary to reexamine the existing techniques and come up with more appropriate intermolecular force models.

It is understood that formidable challenges remain in the fundamental understanding of various phenomena in nanoscale before the potential of nanotechnology becomes a reality. With the knowledge of better and more exact intermolecular interactions between atoms and molecules it will become possible to increase our fundamental...