University of KashanIranian Journal of Mathematical Chemistry2228-64891Issue 1 (Special Issue on the Role of PI Index in Nanotechnology)20100401Use of Structure Codes (Counts) for Computing Topological Indices of Carbon Nanotubes: Sadhana (Sd) Index of Phenylenes and its Hexagonal Squeezes9194513810.22052/ijmc.2010.5138ENP. E.JOHNTechnische Universitat Iimenau, IlmenauS.AZIZDepartment of Applied Sciences (Mathematics), IndoreP. V.KHADIKARLaxmi Fumigation and Pest Control, Khatipura, India.Journal Article20140420Structural codes vis-a-vis structural counts, like polynomials of a molecular graph, are important in computing graph-theoretical descriptors which are commonly known as topological indices. These indices are most important for characterizing carbon nanotubes (CNTs). In this paper we have computed Sadhana index (Sd) for phenylenes and their hexagonal squeezes using structural codes (counts). Sadhana index is a very simple W-Sz-PItype topological index obtained by summing the number of edges on both sides of the elementary cuts of benzenoid graphs. It has the similar discriminating power as that of the Weiner (W)-, Szeged (Sz)-, and PI-indices.https://ijmc.kashanu.ac.ir/article_5138_27ded09e0fb14ea6a65bfd0082c84828.pdf