It will be shown that the Electron Localization Function, ELF, can also be used to study the delocalization and aromatic character of a diversity of molecules. Although the analysis of the total ELF does not provide clear information about aromaticity, the separation of the function on its σ and π parts yields indeed valuable ...[+]

It will be shown that the Electron Localization Function, ELF, can also be used to study the delocalization and aromatic character of a diversity of molecules. Although the analysis of the total ELF does not provide clear information about aromaticity, the separation of the function on its σ and π parts yields indeed valuable information about it. Moreover, it is possible to construct a quantitative scale of aromaticity. It is also shown that the use of the ELF to understand aromaticity is complementary to other methodologies. Applications to organic and inorganic molecules and atomic clusters demonstrate the capability of the method and the possibility of distinguish between σ , π , δ… aromaticity[-]