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Extremal values of vertex‐degree‐based topological indices of coronoid systems
Author(s) -
Cruz Roberto,
SantamaríaGalvis Andrés David,
Rada Juan
Publication year - 2021
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.26536
Subject(s) - combinatorics , vertex (graph theory) , degree (music) , topological index , graph , mathematics , topology (electrical circuits) , physics , acoustics
A vertex‐degree‐based (VDB for short) topological index φ induced by the numbers { φ i , j } , is defined for a graph G with n vertices as 1 φ G = ∑ 1 ≤ i ≤ j ≤ n − 1m i , jφ i , j , where m i , j is the number of edges in G joining vertices of degree i and j . Our main concern is to study VDB topological indices over important classes of coronoid systems. Recall that a coronoid system is a natural representation of a coronoid hydrocarbon and can be defined as a benzenoid‐like system with a hole. In this paper we determine the extremal values of a VDB topological index φ over the set of primitive coronoid systems, the set of catacondensed coronoid systems, and the set of circumscribed coronoid systems.