Estudo da aplicação e interpretação do teorema virial para moleculas poliatomicas

AUTOR(ES)
DATA DE PUBLICAÇÃO

1992

RESUMO

The virial theorem was applied to the construction of same type of Walsh´s correlation diagrams. When using approximate wave functions (CNDO/2) demonstrated an excellent accordance with the ones obtained experimentally (please note that: Q = 0, ± 1 and A the second line elements of the periodic table). The kinetic energy diagrams constructed to the group of molecules that have the central atom with atomic number smaller than six are different of the ones constructed to the group of molecules with the central atom with atomic number greater than six. We made partitions of the molecular orbitals kinetic energies and observe that to the first group, the overlap kinetic energy determines the maximum and minimum of the kinetic energies. To the molecules of the second group the atomic orbitals kinetic energies are the more important terms. Comparing the kinetic energies fragments with the Mulliken´s gross and overlap sub-populations we could understand that the increase or decrease of these sub-populations are responsible for the increase or decrease of the kinetic fragments. As a consequence of the virial theorem we establish the principle of maximum kinetic energy and could evaluate which were the molecular orbitals responsible for the molecular geometry. The study of the behavior of the molecular orbitals kinetic energies shows up that, when we add or remove an electron of a molecule we can maintain some relation with the valence shell electron pair repulsion model. By means of very simple rules we constructed qualitatively the kinetic energy diagrams showing the simplicity of the behaviour of the kinetic energies. Many comparisons with different methods were made but, until now, we could not establish a paralellism between the behaviour of the kinetic energies and other energetic entities.

ASSUNTO(S)

moleculas fisica nuclear modelos quimicos

ACESSO AO ARTIGO

Documentos Relacionados