The edge version of Szeged index and vertex version of PI index are defined very recently. They are similar to edge-PI and vertex-Szeged indices, respectively. The different versions of Szeged and PIindices are the most important topological indices defined in Chemistry. In this paper, we compute the edge-Szeged and vertex-PIindices of some important classes of benzenoid systems.

Abstract Aromatic chemicals play indispensable roles in our daily lives, having broad applications household goods, textiles, healthcare, electronics and automotive, but their production currently relies on fossil resources that have heavy environmental burdens. Synthesis of aromatic from bio-based would be a viable approach to improve sustainability. However, very few methods are available for...

A VDB topological index is defined as

The main topological characteristics of altan-benzenoids were established. In particular, it was shown that the perimeter of Kekuléan altan-benzenoids is of size 4k , having a destablizing (anti-aromatic) energy effect, similar to (4k)-annulenes.