Mohammad Shahryari - Department of Mathematics, College of Science, Sultan Qaboos University, Muscat, Oman
Gholamreza Vakili-Nezhaad - Department of Petroleum and Chemical Engineering, College of Engineering, Sultan Qaboos University, Muscat, Oman

We introduce a fast method of computing the topological charge indices of simple graphs (molecules) which does not require matrices of large sizes. For the case of trees, we give a compact formula and in the general case we obtain upper and lower bounds for the charge indices. We give concrete examples of trees and molecules with their charge indices computed using our method.

Topological charge index, Valence topological charge index, Elegctronegativity, Simple garphs, graph invariants