ABSTRACT
The electromagnetic interaction in the system of many particles in water appears in the form of exchange, multipole, fluctuation, and other interaction forces. Among such interaction forces, one can distinguish those that deplete at large distances as a power function. Such forces are frequently called long-range forces in contrast to short-range forces that deplete rapidly (usually exponentially) with the increase of distance. The short-range forces-distance type of dependence is not most often universal and can be determined by a certain structure of electron shells of atoms. The distinctive feature of long-range forces is, on the contrary, known versatility of their behavior at long distances. At that, if the average charge density and average dipole moment density are equal to zero in an equilibrium medium, then the main long-range forces, in general, are the forces of fluctuation origin that are frequently called the van der Waals forces. They can be calculated by the quantum mechanical approach, but meanwhile accurate values are provided by experimental measurements.
