### فهرست مطالب

• Volume:5 Issue: 1, Summer Autumn 2015
• تاریخ انتشار: 1394/12/18
• تعداد عناوین: 6
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The eccentric connectivity index of a graph is defined as E(Γ)=∑uεV(Γ)degΓ(u)e(u), where degΓ(u) denotes the degree of the vertex u in Γ and e(u) is the eccentricity of vertex u. In this paper, the modified eccentric connectivity index of two infinite classes of fullerenes is computed
Keywords: automorphism group, eccentric connectivity index, fullerene graph
• Roya Majidi* Pages 11-22

Modifying the electronic properties of graphyne via doping, organic molecule adsorption, and chemical functionalization was reviewed. The electronic band structure and density of states were studied by using density functional theory. The α-graphyne was considered due to its analogous to graphene. The results indicate α-graphyne is a semimetal with zero band gap. It was shown that doping, adsorbing organic molecule, and chemical functionalization can open a band gap in α-graphyne. The size of the band gap was dependent on the concentration of impurity, adsorbed TCNE or CCl2 molecules. The mentioned methods provide the possibility of opening an energy band gap in α-graphyne as required for fabricating high-performance nanoelectronic devices based on graphyne

Keywords: α, graphyne, doping, organic molecule adsorption, functionalization, electronic
The geometric-arithmetic index is a topological index was defined as $GA(G)=\sum{uv\in E(G)}\frac{2\sqrt{d_ud_v}}{d_u_v}}$, where du denotes the degree of vertex u in G. By replacing instead $\delta_u=\sum_{v\cong u} d_v$ of du in GA(G), we have a new version of this index that defined as $GA(G)=\sum{uv\in E(G)}\frac{2\sqrt{\delta_u\delta_v}}{\delta_u\delta_v}}$. In this paper, we present exact formulas of these indices for some benzenoid graphs