The degree distance of a graph which is a degree analogue of the Wiener index of the graph. Let G = TUV C6[2p, q] be the carbon nanotubes covered by C6, formulas for calculating the degree distance of armchair polyhex nanotubes TUV C6[2p, q] are provided. Mathematics Subject Classification: 05C05, 05C12

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 study of topological indices - graph invariants that can be used for describing and predicting physicochemical or pharmacological properties of organic compounds - is currently one of the most active research fields in chemical graph theory. In this paper we study the Schultz index and find a relation with the Wiener index of the armchair polyhex nanotubes TUV C(6)[2p; q]. An exact expressi...

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...

Abstract Topological indices of nanotubes are numerical descriptors that are derived from graph of chemical compounds. Such indices based on the distances in graph are widely used for establishing relationships between the structure of nanotubes and their physico-chemical properties. The Szeged index is obtained as a bond additive quantity where bond contributions are given as the product of th...

Let G be a simple connected graph with the vertex set V = V(G) and the edge set E = E(G), without loops and multiple edges. For counting qoc strips in G, Omega polynomial was introduced by Diudea and was defined as Ω(G,x ) = ( , ). , c c m G c x  where m(G,c) be the number of qoc strips of length c in the graph G. Following Omega polynomial, the Sadhana polynomial was defined by Ashrafi et al ...

Using density-functional theory the stability of armchair and zigzag single-walled carbon nanotubes and graphene nanoribbons was investigated. We found that the stability of armchair and zigzag nanotubes has different linear dependence with regard to their length, with switches in the most stable chirality occurring at specific lengths for each nanotube series. We explain these dependencies by ...

Abstract: The Hosoya polynomial of a molecular graph G is defined as ∑ ⊆ = ) ( } , { ) , ( ) , ( G V v u v u d G H λ λ , where d(u,v) is the distance between vertices u and v. The first derivative of H(G,λ) at λ = 1 is equal to the Wiener index of G, defined as ∑ ⊆ = ) ( } , { ) , ( ) ( G V v u v u d G W . The second derivative of ) , ( 2 1 λ λ G H at λ = 1 is equal to the hyper-Wiener index, d...