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GAP Programming
Published in Mihai V. Putz, New Frontiers in Nanochemistry, 2020
Yaser Alizadeh, Ali Iranmanesh
A topological index of a molecular graph is a real number derived from the structure of the graph such that isomorphic graphs have the same topological index. The study of topological indices based on distance in a graph in biological sciences, physical chemistry and QSAR and QSPR studies started from 1947 when Harold Wiener introduced the Wiener index to establish the relationships between physico-chemistry properties of alkenes and the structures of their molecular graphs. Wiener index, Szeged index, edge Wiener index, eccentric connectivity index are some of the well-known topological indices. In a series of papers, topological indices were computed for some nanostructure nanotubes and fullerenes. For example, these topological indices were obtained for C12k+4 fullerenes in Alizadeh et al., (2012) for coronene/circumcoronene in Alizadeh & Klavzar (2013), for benzenoid hydrocarbon and phenylenes in Gutman & Klavzar (1996). In some other papers by using the GAP program, the topological indices were calculated for some nanotubes and fullerenes such as C80 fullerene HAC5C7[p,q] and HAC5C6C7[p,q] nanotubes (see Iranmanesh et al., 2009; Iranmanesh & Alizadeh, 2013).
Structure–activity relations for antiepileptic drugs through omega polynomials and topological indices
Published in Molecular Physics, 2022
Medha Itagi Huilgol, V. Sriram, Krishnan Balasubramanian
In chemical graph theory, the Szeged index is a topological index of a molecule, used in biochemistry. The Szeged index, introduced by Gutman [68], generalises the concept of the Wiener index. Szeged index has been shown to correlate well with numerous biological and physicochemical properties. Khadikar and coauthors [69] investigated numerous chemical and biological applications of PI index and they found PI index superior to both Wiener and Szeged indices. Similarly, Mostar and Harmonic Szeged index are important discriminators in chemical graph theory. As given in Table 1, each of the degree-based index has a neighbourhood degree-based counterpart. And each of these can be derived using NM-polynomial as given in Table 2.