Extremal symmetric division deg index of molecular trees and molecular graphs with fixed number of pendant vertices

In 2018, Furtula et al. proved that the symmetric division deg index is a viable and applica-ble topological index in QSPR/QSAR investigations. In this article, we identify the extremal trees with respect to symmetric division deg index among all molecular trees with fixed number of pendant vertices. In addition, we get a lower bound on symmetric division deg index for all molecular (n, m, p)-graphs ( n-order molecular graphs with m >= n edges and p > 0 pendant vertices). (c) 2022 Elsevier Inc. All rights reserved.