GIAO-MNDO

Nucleus-independent chemical shifts, introduced by Schleyer et al. as a measure for aromaticity [20], can also be computed at the GIAO-MNDO level of theory, making this useful tool also available to much larger aromatic structures such as graphenes and fullerenes [21]. The ab initio reference data are generally reproduced well, but four-membered rings are still problematic. The aromatic properties of Hiickel-type hydrocarbons, Mobius aromatics, and three-dimensional cage com-... 

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