Available datasets to study using Hückel theory

I'm trying to do some tests using graph Laplacians based on Hückel theory. This, however, is said to be only applicable for conjugated hydrocarbons. My questions are:


1. I have been working with QM9 dataset and I was wondering if QM9 passes the filter (being consist of conjugated hydrocarbons only). How about ZINC database?
2. Are there any datasets available that can be analyzed using Hückel theory (Preferably with their SMILES representations included, and some property value reported, for testing a prediction algorithm)?


