Hello,

normally, you would model the cluster and the monomers and optimize the structures. Then, just add up the monomer energies and substract from the cluster energy.

Or did I not get the point?

Cheers,

Arnim

which type of basic set? TZVP or another else?

Since you want to treat anions, you should consider diffuse basis functions. That, however, can lead to an increase of the BSSE.

Therefore, you should try to be as complete as possible with the basis set.

I would try the def2-QZVPD.

so first i draw the molecule together with cation and anion using turbomole and choose def2-QZVPD.Then i get the data like kinetics etc then i just minus the energy each of sole molecule right sir?

Please have a look at this:

https://en.wikipedia.org/wiki/Interaction_energy

Thank you sir for your time to reply and enlighten this knowledge to me. Hope we can collaborate in the future .