Results 11 to 20 of about 73,915 (253)
Electron Energy Studying of Molecular Structures via Forgotten Topological Index Computation
Journal of Chemistry, 2016 It is found from the earlier studies that the structure-dependency of total π-electron energy Eπ heavily relies on the sum of squares of the vertex degrees of the molecular graph. Hence, it provides a measure of the branching of the carbon-atom skeleton.
Wei Gao +3 more
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Initial-state radiation measurement of the e^+e^- → π^+π^-π^+π^- cross section [PDF]
, 2012 We study the process e^+e^-→π^+π^-π^+π^-γ, with a photon emitted from the initial-state electron or positron, using 454.3 fb^(-1) of data collected with the BABAR detector at SLAC, corresponding to approximately 260 000 signal events.
Doll, D. A. +8 more
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Topology and stability of conjugated hydrocarbons: The dependence of total π-electron energy on molecular topology [PDF]
Journal of the Serbian Chemical Society, 2005 In spite of the fact that research on the mathematical properties of the total π-electron energy E (as computed by means of the Hückel molecular orbital approximation) started already in the 1940s, many results in this area have been obtained also in the
Gutman Ivan
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Stability of bicalicene isomers: A topological study [PDF]
Journal of the Serbian Chemical Society, 2016 Bicalicene is the conjugated hydrocarbon obtained by joining two calicene fragments. This can be done in two different ways, thus resulting in two bicalicene isomers (tentatively referred to as cis and trans).
Gutman Ivan
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The Hall rule in fluoranthene-type benzenoid hydrocarbons [PDF]
Journal of the Serbian Chemical Society, 2008 The applicability of the Hall rule (linear relation between the total π-electron energy and the number of Kekulé structures) was investigated in the case of fluoranthene-type benzenoid hydrocarbons. It was found that the originnal Hall rule is not obeyed,
Đurđević Jelena +2 more
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The total π-electron energy saga: Continuation [PDF]
Kragujevac Journal of ScienceThe total π-electron energy, as calculated within the Hückel molecular orbital approximation, is a much studied quantum chemical characteristics of unsaturated conjugated compounds. Its theory, together with that of its modification called "graph energy",
Gutman Ivan
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A graph theoretical approach to cis/trans isomerism [PDF]
Journal of the Serbian Chemical Society, 2014 A simple graph-theory-based model is put forward, by means of which it is possible to express the energy difference between geometrically non-equivalent forms of a conjugated polyene.
Furtula Boris +2 more
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Aromaticity of aza aromatic molecules: prediction from Hückel theory with modified parameters [PDF]
Química Nova, 2023 Hückel theory is a simple and powerful method for predicting the molecular orbital and the energy of conjugated molecules. However, the presence of nitrogen atoms in aza aromatic molecules alters the Coulomb and resonance integrals owing to the ...
Inge M. Sutjahja +3 more
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Computing graph energy: An alternative approach [PDF]
Kragujevac Journal of Science, 2014 The characteristic polynomial corresponding to the adjacency matrix of a graph is obtained by the Faddeev-Leverrier algorithm. Subsequently, an improved numerical scheme, based on the Newton-Raphson algorithm and the Adomian decomposition method, is ...
Fatoorehchi Hooman +2 more
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On the spectrum, energy and Laplacian energy of graphs with self-loops
Heliyon, 2023 The total energy of a conjugated molecule's π-electrons is a quantum-theoretical feature that has been known since the 1930s. It is determined using the Huckel tight-binding molecular orbital (HMO) method.
Ugasini Preetha P +2 more
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