Electronic theory of molecule vibrations

In this contribution we report on the electronic theory of molecule vibrations. We have analyzed the main ideas and principles lying at the heart of mechanistic approach. It was shown that its accuracy is insufficient. To improve the accuracy, it is necessary to introduce the interaction of electron motion with vibrations of nuclei. It was done with the help of conception of binding and unshared electron pairs repelling each other. Although this conception has explained geometric structure of many molecules, it has a static nature. Transformation of this conception into equations of motion allowed us to assign a clear physical sense to elastic constants used in common theories as input parameters. It is shown that the elastic constant of deformation vibration is determined by the repulsion of bond-charges. In the framework of the theory developed, normal valence vibrations are not independent and connected with deformation vibrations. After applying the corrections one can improve significantly the accuracy of prediction and obtain a good agreement with experimental data. Electro-elastic parameters calculated for some molecules on the basis of the theory submitted are also given.