In chemical graph theory, many graph parameters, or topological indices, were proposed as estimators of molecular structural properties. Often several variants of an index are considered. The aim is to extend the original concept to larger families of graphs than initially considered, or to make it more precise and discriminant, or yet to make its range of values similar to that of another inde...

We show that on cactus graphs the Szeged index is bounded above by twice Wiener index. For revised situation reversed if graph class further restricted. Namely, all blocks of a are cycles, then its below Additionally, we these bounds sharp and examine cases equality. Along way, provide formulation as sum over vertices, which proves very helpful, may be interesting in other contexts.

The edge-Szeged index is recently introduced graph invariant, having applications in chemistry. In this paper, a method of calculating the edge-Szeged index of hexagonal chain is proposed, and the results of the index are presented.

hansen et‎. ‎al.‎, ‎using the autographix software ‎package‎, ‎conjectured that the szeged index $sz(g)$ and the‎ ‎wiener index $w(g)$ of a connected bipartite graph $g$ with $n geq ‎4$ vertices and $m geq n$ edges‎, ‎obeys the relation‎ ‎$sz(g)-w(g) geq 4n-8$‎. ‎moreover‎, ‎this bound would be the best possible‎. ‎this paper offers a proof to this conjecture‎.

topological indices are numerical parameters of a graph which characterize its topology. inthis paper the pi, szeged and zagreb group indices of the tetrameric 1,3–adamantane arecomputed.

We study distance-based graph invariants, such as the Wiener index, the Szeged index, and variants of these two. Relations between the various indices for trees are provided as well as formulas for line graphs and product graphs. This allows us, for instance, to establish formulas for the edge Wiener index of Hamming graphs, C4nanotubes and C4-nanotori. We also determine minimum and maximum of ...

The weighted Szeged index of a connected graph G is defined as Szw(G) = ∑ e=uv∈E(G) ( dG(u) + dG(v) ) nu (e)n G v (e), where n G u (e) is the number of vertices of G whose distance to the vertex u is less than the distance to the vertex v in G. In this paper, we have obtained the weighted Szeged index Szw(G) of the splice graph S(G1, G2, y, z) and link graph L(G1, G2, y, z).

Let (G,w) be a network, that is, a graph G = (V (G), E(G)) together with the weight function w : E(G) → R. The Szeged index Sz(G,w) of the network (G,w) is introduced and proved that Sz(G,w) ≥ W (G,w) holds for any connected network where W (G,w) is the Wiener index of (G,w). Moreover, equality holds if and only if (G,w) is a block network in which w is constant on each of its blocks. Analogous...