The Padmakar-Ivan (PI) index is a Wiener-Szeged-like topological index, which reflects certain structural features of organic molecules. In this paper, we study the maximum PI indices and the minimum PI indices for trees and unicyclic graphs respectively.

The electric quadrupole, hexadecapole moments, energy (kJmol -1) for some armchair polyhex carbon nanotubes TUVC6[2p,q] are performed by Beck-Lee-Yang-Parr [B3LYP] on 3-21G basis set using the standard procedure indices GAUSSIAN 98, then the Padmakar-Ivan (PI) index of TUVC6[2p,q] nanotubes in the terms of their circumference (2p) and lengh (q) is calculated and the relationships between the Pa...

The Padmakar–Ivan index of a graph G is the sum over all edges uv of G of number of edges which are not equidistant from u and v. In this work, an exact expression for the PI index of the Cartesian product of bipartite graphs is computed. Using this formula, the PI indices of C4 nanotubes and nanotori are computed. c © 2007 Elsevier Ltd. All rights reserved.

In this survey article a brief account on the development of Padmakar-Ivan (PI) index in that applications of Padmakar-Ivan (PI) index in the fascinating field of nano-technology are discussed.

Recently the vertex Padmakar–Ivan (PI v) index of a graph G was introduced as the sum over all edges e = uv of G of the number of vertices which are not equidistant to the vertices u and v. In this paper the vertex PI index and Szeged index of bridge graphs are determined. Using these formulas, the vertex PI indices and Szeged indices of several graphs are computed.

in this survey article a brief account on the development of padmakar-ivan (pi) index in thatapplications of padmakar-ivan (pi) index in the fascinating field of nano-technology arediscussed.

The Padmakar-Ivan (PI) index of a graph G is the sum over all edges uv of G of the number of edges which are not equidistant from u and v. In this paper, the notion of vertex PI index of a graph is introduced. We apply this notion to compute an exact expression for the PI index of Cartesian product of graphs. This extends a result by Klavzar [On the PI index: PI-partitions and Cartesian product...

the electric quadrupole, hexadecapole moments, energy (kjmol -1) for some armchair polyhex carbon nanotubes tuvc6[2p,q] are performed by beck-lee-yang-parr [b3lyp] on 3-21g basis set using the standard procedure indices gaussian 98, then the padmakar-ivan (pi) index of tuvc6[2p,q] nanotubes in the terms of their circumference (2p) and lengh (q) is calculated and the relationships between the pa...

The Padmakar–Ivan (PI) index of a graph G is defined as the sum of terms [mu(e) + mv(e)] over all edges of G, where e is an edge, connecting the vertices u and v, wheremu(e) is the number of edges of G lying closer to the vertex u than to the vertex v, and where mv(e) is defined analogously. The extremal values of the PI index are determined in the class of connected bipartite graphs with a giv...