Face index computation of certain polycyclic aromatic hydrocarbons

The face index is a topological descriptor that provides insights into the molecular architecture of PAHs, which are significant due to their environmental persistence and potential health impacts. By analyzing the graphical representations of these compounds, we derive mathematical expressions for their face indices, highlighting the relationships between their structural features and chemical properties. Our findings contribute to a deeper understanding of how molecular structure influences the behavior of PAHs, paving the way for further research in both theoretical and applied chemistry contexts. This study not only enhances the characterization of complex PAH structures but also serves as a foundation for future investigations into their environmental and toxicological implications. We focus on Hexa-cata-hexa-benzocoronene and Dodeca-benzo-circumcoronene and derive analytical expressions for their face index based on their molecular graphs.