Simple principle of structure-energy conformity and its use for the modeling of the interaction between hydrogen molecules

In principle, several relationships can be devised which determine approximately the energy of the system. Each of them represents the formulation of a principle of structure-energy conformity (SEC), since in these functions a certain energy value is attributed to a given configuration of the system. One of the simplest priciples of SEC can be formulated within the framework of the perturbation theory or the theory of perturbed molecular orbitals (PMO). In the present work a formulation of this principle is presented based on which the physical sense of simpler formulations of the SEC principle is interpreted. This principle is also used to simulate the interaction between hydrogen molecules.