Ring current maps

Havenith RWA, De Proft F, Fowler PW, GeerUngs P (2004) o-aromadcity in and Li insights from ring-current maps. Chem Phys Lett 407 391—396... 

As tools for measuring electron delocalization, we opt for the visual inspection of the occupied orbitals and especially the so-called domain-averaged Fermi-hole (DAFH) analysis and MCI. Both of these require availability of atomic overlap matrices, where the overlap between two molecular orbitals is obtained in atom condensed form. This requires the definition of an atom in the molecule and in this study we chose the Ftirshfeld-I method. Finally, we introduce ring current maps in the ipso-centric approach. 

All geometry optimizations were performed using the Gaussian03 program [84]. All calculations of Hirshfeld-I data, DAFH, MCI, and ring current maps were carried out using own codes. 

HF/6-311G Ring Current Maps Computed Unit Above and Below (where Different Above) in LiAlj... 

Orbital Resolved Ring Current Maps in the AI4 Plane in AI4 Except for the HOMO Where it is Evaluated at 1 au Above the Plane... 

It has been shown that there is no direct relation between electron delocalization and the presence of a ring current, other than that a delocalized system is a necessary but not sufficient condition to lead to a ring current. In the case of Al " derived compounds, there is clearly both o and n electron delocalization although only the a system gives rise to a ring current. The analysis of CMO-NICS data is shown to lead to a different conclusion although this method also contains occupied-occupied terms and is not so easily interpretable as ipsocentric ring current maps. 

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