Multiwfn forum

Hello, my name is Alex, I'm trying to study a deprotonation process using DFT, for that I'm optimizing protonated and deprotonated structures using M062X and gen keyword (3-21g/6-31+(d)) (https://pubs.acs.org/doi/abs/10.1021/jp3089947 and I'm using M062X instead of B3LYP because it gave better energetic results in my case) in the gas phase and with the SMD solvent model, this way I should be able to calculate pKa values. However, the system I'm using has 3 identical solvent exposed groups capable of deprotonation and altough these being covalently attached to a carbon nanotube they have great conformational flexibility, so I assume the deprotonation process of all groups is somewhat complex. Can I have your advice on this please? Also, does multiwfn software offer a way to evaluate acid dissociation? Is there any problem in using M062X functional, should I use D3 corrections? Thank you for your time!