Department of Chemistry, St Petersburg State University, St Petersburg, Russia.
In nuclear physics and elementary particle theory, on understanding of symmetry and associated concepts of the hierarchy of interactions play a fundamental role . Thus the relative insignificance of electromagnetic and weak interactions as compared with the strong interaction of nucleons in the nucleus enables a model of the nucleus to be examined in the limit of precise symmetry of strong interactions. In such a model, the, protons and neutrons become physically indistinguishable states of a nucleon, while the properties of the nucleus become invariant relative to isotopic transformations.
It is also possible to speak of the hierarchy of interactions participating In the formation of molecules. The energy of chemical bonds, which is 1-2 orders of magnitude greater than the energy of non-valent interactions, can be given as on example of “strong” interaction. Another example relates to the case when the energy of the valence interactions is much higher than the energy of intermolecular bonds in a condensed medium.
Weak interactions in chemistry are normally taken into account by introducing different perturbations into physical models. These perturbations are generally unmeasured parameters that are basically the adjustable magnitudes.
However, in the chosen class of molecules an attempt can be made to find the ratios of values of the examined parameter in which the contributions of “weak” interactions are
The search for such relationships and ratios is the purpose of this work.
Keywords: group theory, symmetry groups, molecular symmetry group, invariants for molecules.
Pages: 51 – 54 | Full PDF Paper