Chemical shifts calculations on aromatic systems: a comparison of models and basis sets

GIAO and CSGT models at Hartree–Fock and DFT/B3LYP levels of theory using different basis sets were employed for calculations of 1H and 13C NMR chemical shifts for para-X-substituted (X = H, CH3O and NO2) aromatic carbonyl compounds. For these compounds the best choice to evaluate theoretical chemical shifts is B3LYP/cc-pVDZ using CSGT model.