The second geometric-arithmetic index GA2(G) of a graph G was introduced recently by Fath-Tabar et al. [2] and is defined to be ∑ uv∈E(G) √ nu(e,G)nv(e,G) 1 2 [nu(e,G)+nv(e,G)] , where e = uv is one edge in G, and nu(e,G) denotes the number of vertices in G lying closer to u than to v. In this paper, we characterize the tree with the minimum GA2 index among the set of trees with given order and...

The Szeged index (Sz) is a recently proposed1q2 structural descriptor, based on the distances of the vertices of the molecular graph. In order to be able to study the properties of this novel topological index it would be advantageous to possess an easy method for its calculation. The calculation of Sz directly from its definition (see below) is quite cumbersome, especially in the case of large...

Let G= V E be a simple connected graph. The distance between two vertices of G is defined to be the length of the shortest path between the two vertices. There are topological indices assigned to G and based on the distance function which are invariant under the action of the automorphism group of G. Some important indices assigned to G are the Wiener, Szeged, and PI index which we will find th...

The mathematical properties of nano molecules are an interesting branch of nanoscience for researches nowadays. The periodic open single wall tubulene is one of the nano molecules which is built up from two caps and a distancing nanotube/neck. We discuss how to automatically construct the graph of this molecule and plot the graph by spring layout algorithm in graphviz and netwrokx packages. The...

a Department of Inorganic and Analytical Chemistry, University of Szeged, Dóm tér 7. H-6720 Szeged, Hungary 8 b MTA-SZTE Bioinorganic Chemistry Research Group, University of Szeged, Dóm tér 7. H-6720 Szeged, 9 Hungary 10 c Centro de Química e Bioquímica (CQB), Faculdade de Ciências, ULisboa, Campo Grande, Lisbon, Portugal 11 d Centro de Química Estrutural (CQE), Faculdade de Ciências, ULisboa, ...

Topological indices are numerical parameters of a graph which characterize its topology. In this paper the PI, Szeged and Zagreb group indices of the tetrameric 1,3–adamantane are computed.

Katinka Ónodi-Nagy1*, Zsuzsanna Bata-Csörgő1, Erika Varga1, Lajos Kemény1 and Ágnes Kinyó1,2 1Department of Dermatology and Allergology, University of Szeged, Albert Szent-Györgyi Medical Center, Hungary 2Department of Dermatology, Venereology and Oncodermatology, University of Pécs, Hungary *Corresponding author: Katinka Ónodi-Nagy, Department of Dermatology and Allergology, University of Szeg...