The Graph-Theoretical Descriptors for Carbon Nanotubes (CNTs): Sadhana (Sd) Index of Phenylene (PH) and Its Hexagonal Squeeze (HS)

摘要

The Sadhana index, abbreviated as Sd, is a very simple W-Sz-Pl—type topological index obtained by summing the number of edges on both sides of the elementary cuts of benzenoid graphs. The Sd index has the similar discriminating power as that of Wiener (W), Szeged (Sz) and PI indices. A mathematical formula for calculating the Sd index of phenylene (PH) and its hexagonal squeeze (HS) is derived. A simple relation between the two is also given.