Electronic structure and symmetry in conjugated π-electron systems

The continuous symmetry measures (CSM) method has been used to study the π-electron systems for a diverse set of molecules, illustrating the capabilities of this new analytical tool to quantify the changes in the electronic structure of molecules upon symmetry breaking perturbations induced either by geometry modifications or chemical substitutions. The symmetry analysis applied to the Hamiltonian, the molecular orbitals or the electron density obtained from a simple Hückel model for these compounds reveals the basic relations between symmetry and the electronic structure. Calculation of continuous symmetry measures from ab initio calculations confirms these relations, allowing at the same time a much more accurate description of the influence of symmetry on the electronic structure of these compounds.