Dear Turbasu,

maybe a bit off-topic: did you try to visualize and analyze molecular orbitals of your structures? Do you work with organic molecules or metal clusters?

Best regards,

Aleksey.

Dear Turbasu,

Yes, NICS values are indeed very sensitive to the methods/basis sets employed.  You can't compare two NICS values obtained by different methods/basis sets. But you can always compare NICS values obtained by same method/basis set for different systems. Please note that NICS is the most popular measure of aromaticity. You can also calculate HOMA indices as well, but  it is somewhat tricky to choose correct parameters for particular system. You don't need any software to do that, you have to calculate it manually..

Dear Aleksey,

I work with metal clusters hence aromaticity parameters based on bond length won't work also I think by observing the MO of metal clusters will not be much beneficial to determine the trends.However I'm not so sure about it.What's your opinion?

Dear Turbasu,

Did you try to make NBO analysis? It could help you to determine aromacity in your compounds.

Dear Wojciech,

I know how to do a NBO analysis but I've no idea how to be confirmed about aromaticity from D-A interaction energies.Any help will be highly appreciated.

Hi, I am not pretty sure what is your exact problem. From NBO analysis you will be able to see if your electrons are highly delocalized or not. And it will be as well the answer for your question.

Dear Turbasu,

apologies for the belated reply: I will highly recommend you to look at the works of Dr. Alexander Boldyrev (some of those are co-authored by me, too), Utah State University, he is a guru in all-metal aromaticity (ion.chem.usu.edu/~boldyrev/). I'm attaching one of his very recent reviews on this issue.

With best regards,

Aleksey.