Background: Recently, the author of the article proposed a new index for the estimation of the aromatic
character. The aromaticity index D, D usually obtained by using
DFT/B3LYP/6-311G+(d,p) theoretical method.
Method: The D index was tested using different functionals: LSDA, BVP86, B3LYP, CAM-B3LYP, B3PW91,
mPW1PW91, PBEPBE, HSE1PBE, HCTH, TPSSTPSS, and wB97XD.
Results: The results showed that the D values for monocyclic aromatic compounds are not largely sensible to the variation
of the functional. Large variations of D values were observed for polycyclic aromatic compounds. D values were correlated
to ERE (experimental resonance energy) and ASE (aromatic stabilization energy). ERE and ASE gave different correlations
Conclusion: The best correlation between D and ERE was obtained by using CAM-B3LYP. The best correlation between
D and ASE was obtained by using CAM-B3LYP.