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Density functional study on structural and electronic properties of bimetallic gold-yttrium clusters: comparison with pure gold and yttrium clusters

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Chinese Physics B 2008年第6期17卷 2110-2115页

作者：毛华平王红艳盛勇 Department of Chemistry and Environment Engineering Chongqing Three-Gorge College Institute of Atomic and Molecular Physics Sichuan University Department of Chemistry and Center for Computational Chemistry University of Georgia Material Science and Engineering College Sichuan University

Employing first-principles methods, based on the density functional theory, this paper investigates the ground state geometric and electronic properties of pure gold clusters, pure yttrium clusters and gold clusters doped each with one yttrium atom. It is shown that the average bond lengths in the Aun-1Y（n≤9） bimetallic clusters are shorter than those in the corresponding pure gold and yttrium clusters. The most stable isomers of the yttrium-doped gold clusters tend to equally delocalize valence s, p and d electrons of the constituent atoms over the entire structure. The Y atom has maximum number of neighbouring Au atom, which tends to be energetically favourable in the lowest-energy equilibrium structures, because the Au-Y bond is stronger than the Au-Au bond. The three-dimensional isomers of Aun-1Y structures are found in an early appearance starting at n=5 （Au4Y）. Calculated vertical ionization potential and electron affinities as a function of the cluster size show odd-even oscillatory behaviour, and resemble pure gold clusters. However, one of the most striking feature of pure yttrium clusters is the absence of odd-even alternation, in agreement with mass spectrometric observations. The homo lumo gap of Au3Y is the biggest in all the doped Aun-1Y（n≤9） bimetallic clusters.

关键词： gold-yttrium bimetallic cluster density functional theory homo-lumo gap equilib- rium structure

A Density Functional Investigation of Fluorinated Silicon Clusters

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Chinese Journal of Chemistry 2011年第4期29卷 735-740页

作者：王宏武林 College of Mathematics Physics and Information Engineering Zhejiang Normal University Jinhua Zhejiang 321004 China

Density functional calculations have been carried out on a series of fluorinated empty cages XnFn （n=2-20） with X=Si, Ge, and Sn. It indicates that the fullerene-like cage structure with pentagons turns out to be the most stable with n increasing, and the stability of the XnFn isomers increases with the number of five-membered rings. The homo-lumo gap for Ge （n=6, 10） cages is found to be even larger than the values for Si cages, though in bulk Ge has a smaller band gap than Si. Moreover, calculation of the Gibbs free energy of oligomerization reaction of SiF→1/n （SiF）n showed that this reaction is exothermic even at 900 K, indicating the favorability of their formation from the SiF monomer.

关键词： density functional theory stability binding energy homo-lumo gap

Theoretical Study of Kinetics and Thermodynamics of Hetero Diels-Alder Reaction of Thiazole and Isothiazol with Thiophene-2,5-dione

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Chinese Journal of Structural Chemistry 2011年第10期30卷 1375-1380页

作者： Saeed Reza Emamian Jamileh Nabavi Fatemeh Shams Ehsan Zahedi Chemistry Department Shahrood BranchIslamic Azad University

DFT methods have been used to study the hetero Diels-Alder reaction of thiazole and isothiazole with thiophen-2,*** thermodynamic and kinetic parameters were *** relative stabilities of the transition structures corresponding to the endo/exo stereoisomers have been rationalized on the basis of the secondary molecular orbital *** analysis was carried out to calculate the synchronicity *** was shown that all reactions are synchronous.A homo-lumo energy gap shows both reactions are normal electron demand.

关键词： Diels-Alder DFT kinetics thiazole isothiazole homo-lumo gap

Identification of the Most Stable Sc2C80 Isomers： Structure, Electronic Property, and Molecular Spectra Investigations

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Chinese Journal of Chemistry 2012年第4期30卷 765-770页

作者：吴静怡王太山舒春英吕鑫王春儒 Key Laboratory of Molecular Nanostructure and Nanotechnology Beijing National Laboratory for Molecular SciencesInstitute of ChemistryChinese Academy of Sciences(CAS)Beijing 100190China State Key Laboratory of Physical Chemistry of Solid Surfaces&Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry College of Chemistry&Chemical EngineeringXiamen UniversityXiamenFujian 361005China

A systematic density functional theory investigation has been carried out to explore the possible structures of Sc2C80 at the BMK/6-31 G（d） level. The results clearly show that Sc2@C80-Ih, Sc2@Cso-Dsh, and Sc2C2@C78-C2v can be identified as three isomers of Sc2C80 metallofullerene with the lowest energy. Frontier molecular orbital analysis indicates that the two Sc2@C80 isomers have a charge state as （Sc〉）2@ C60 and the Sc2C2@C78 has a charge state of （Sc3＋）2 C22- @ C784-. Moreover, the metal-cage covalent interactions have been studied to reveal the dynamics of endohedral moiety. The vertical electron affinity, vertical ionization potential, infrared spectra and 13C nuclear mag- netic resonance spectra have been also computed to further disclose the molecular structures and properties.

关键词： metallofullerenes density functional theory relative energy homo-lumo gap

A Density Functional Study of N-Doped TiO_2 Anatase Cluster

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Chinese Journal of Structural Chemistry 2009年第8期28卷 998-1002页

作者：曹飞谭凯林梦海张乾二 State Key Laboratory of Physical Chemistry of Solid Surface & Center for Theoretical Chemistry Departmental of Chemistry College of Chemistry and Chemical Engineering Xiamen University

A systematic study on geometry, electronic structure and vibrational properties of N-doped TiO2 anatase cluster, within the framework of the density functional theory, has been performed in this work. The calculations confirmed that the most structures in substitutional model consist of a two-coordinate bridge structure and a three-coordinate hollow structure. The calculated results can well explain the red shift in N-doped TiO2 observed in experiments. The study provides an illustration for the N-doped anatase from the viewpoint of chemical bonding theory.

关键词： A Density Functional Study of N-Doped TiO2 Anatase Cluster N-doped TiO2 DFT homo-lumo gap

Structures and electronic properties of AUn-1Cu and AUn （n ≤ 9） clusters

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Chinese Physics B 2007年第6期16卷 1660-1664页

作者：王红艳李喜波唐永建 R.Bruce King Henry F.Schaefer III Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China Research Center of Laser Fusion China Academy of Engineering Physical Mianyang 621900 China Department of Chemistry and Center for Computational Chemistry University of Georgia Athens Georgia 30602 USA

A systematic study on the structure and electronic properties of gold clusters doped each with one copper atom has been performed using the density functional theory. The average bond lengths in the Aun-1Cu （n ≤ 9） bimetallic clusters are shorter than those in the corresponding pure gold clusters. The ionization potentials of the bimetallic clusters Aun-1Cu （n 〈 9） are larger than those of the corresponding homoatomic gold clusters except for Aus. The energy gaps of the Au-Cu binary clusters are narrower than those of the Aun clusters except AuCu and Au3Cu. No obvious even-odd effect exists in the variations of the electron affinities and ionization potentials for the Aun-1Cu （n ≤ 9） clusters, which is in contrast to the case of gold clusters Aun.

关键词： Au-Cu bimetallic cluster equilibrium geometry bond energy homo-lumo gap