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Electronic structures of TiN and TiC-Extension of molecular orbital Method into Crystals

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材料科学与工程学报 2000年第Z1期20卷 454-456页

作者： Bin Song Department of Physics and State Key Lab laboratory of Silicon Materials Zhejiang University Hangzhou 310027 State Key Lab laboratory of Silicon Materials Department of Materials Science and Engineering Zhejiang University Hangzhou 310027

Density of states and theoretical X-ray emission spectra for the valence bands of TiN and TiC are obtained with a molecular orbital method. In order to describe electronic structures of crystals, local clusters for the molecular orbital calculations are extended, including the effects from the outside of the cluster in the crystal. The theoretical results are in good agreement with the experimental ones.

关键词： molecular orbital TiN TiC electronic structure extended cluster model

Potential and prospects in molecular orbital level micro-electric field for low energy consumption water purification

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National Science Open 2024年第3期3卷 194-233页

作者： Lai Lyu Yumeng Wang Chao Lu Fan Li Wenrui Cao Yingtao Sun Chun Hu Institute of Environmental Research at Greater Bay Area Key Laboratory for Water Quality and Conservation of the Pearl River DeltaMinistry of EducationGruangzhou UniversityGruangzhou 510006China

Conventional water purification technologies struggle to simultaneously address purification efficiency and energy *** orbital level surface micro-electric field(MEF)-driven water purification is an original and innovative concept conceived and developed by our group in recent *** core idea involves creating electron-rich and electron-poor micro-areas on the nanomaterial surface,which drive pollutants or H_(2)O molecules to provide electrons in the electron-poor micro-areas while other environmental factors(such as H_(2)O_(2)and O_(2))obtain electrons in the electron-rich *** process effectively utilizes the internal energy contained within wastewater and emerging contaminants(ECs).Centered on this core,this review systematically examines the discovery,construction,and characteristics of MEF and MEF-like systems and summarizes their application *** challenges,bottlenecks,and future development directions of MEF technology are also analyzed and *** of MEFs can facilitate the development of low-consumption,high-efficiency water purification technologies.

关键词： molecular orbital micro-electric field low energy consumption water purification pollutant utilization

Conformation effects on the molecular orbitals of serine

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Chinese Physics B 2011年第3期20卷 143-149页

作者：王克栋马鹏飞单旭 Department of Physics Key Laboratory of Photovoltaic Materials of Henan Province Henan Normal University Department of Modern Physics University of Science and Technology of China

This paper calculates the five most stable conformers of serine with Hartree-Fock theory, density functional theory （B3LYP）, Moller-Plesset perturbation theory （MP4（SDQ）） and electron propagation theory with the 6-311＋＋G（2d,2p） basis set. The calculated vertical ionization energies for the valence molecular orbitals of each conformer are in agreement with the experimental data, indicating that a range of molecular conformations would coexist in an equilibrium sample. Information of the five outer valence molecular orbitals for each conformer is explored in coordinate and momentum spaces using dual space analysis to investigate the conformational processes, which are generated from the global minimum conformer Serl by rotation of C2-C3 （Ser4）, C1 C2 （Ser5） and C1-O2 （Set2 and Ser3）. orbitals 28a, 27a and 26a are identified as the fingerprint orbitals for all the conformational processes.

关键词： serine conformers vertical ionization energies molecular orbital momentum distribution

Investigating molecular orbitals with submolecular precision on pristine sites and single atomic vacancies of monolayer h-BN

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Nano Research 2020年第8期13卷 2233-2238页

作者： Liwei Liu Thomas Dienel Gino Günzburger Teng Zhang Zeping Huang Cong Wang Roland Widmer Wei Ji Yeliang Wang Oliver Gröning School of Information and Electronics MIIT Key Laboratory for Low-Dimensional Quantum Structure and DevicesBeijing Institute of TechnologyBeijing100081China Empa Swiss Federal Laboratories for Materials Science and TechnologyDuebendorfCH-8600Switzerland Department of Materials Science and Engineering Cornell University and NSF-MIP Platform for the Accelerated RealizationAnalysisand Discovery of Interface Materials(PARADIM)IthacaNY14853USA Department of Physics and Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-nano Devices Renmin University of ChinaBeijing100872China

Understanding the influence of adsorption sites to the electronic properties of adsorbed molecules on two-dimensional(2D)ultrathin insulator is of essential importance for future organic-inorganic hybrid ***,the adsorption and electronic states of manganese phthalocyanine(MnPc)on a single layer of hexagonal boron nitride(h-BN)have been comprehensively studied by low-temperature scanning tunneling microscopy/spectroscopy and tight binding *** frontier orbitals of the MnPc can change drastically by reversible manipulation of individual MnPc molecules onto and away from the single atomic vacancies at the h-BN ***,the change of the molecular electronic configuration can be controlled depending on whether the atomic vacancy is below the metal center or the ligand of the *** findings give new insight into defect-engineering of the organic-inorganic hybrid nanodevices down to submolecular level.

关键词： hexagonal boron nitride phthalocyanine single atomic vacancy molecular orbital scanning tunneling microscopy

Direct Imaging of molecular orbitals of Metal Phthalocyanines on Metal Surfaces with an O2-Functionalized Tip of a Scanning Tunneling Microscope

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Nano Research 2011年第6期4卷 523-530页

作者： Zhihai Cheng Shixuan Du Wei Guo Li Gao Zhitao Deng Nan Jiang Haiming Guo Hao Tang H. J. Gao Institute of Physics Chinese Academy of Sciences RO. Box 603 Beijing 100190 China Center for Material Elaboration and Structural Studies B.P. 94347 31055 Toulouse Cedex France

High-resolution scanning tunneling microscope images of iron phthalocyanine and zinc phthalocyanine molecules on Au（111） have been obtained using a functionalized tip of a scanning tunneling microscope （STM）, and show rich intramolecular features that are not observed using clean tips. Ab initio density functional theory calculations and extended Huckel theory calculations revealed that the imaging of detailed electronic states is due specifically to the decoration of the STM tip with O2. The detailed structures are differentiated only when interacting with the highly directional orbitals of the oxygen molecules adsorbed on a truncated, [111]-oriented tungsten tip. Our results indicate a method for increasing the resolution in generic scans and thus, have potential applications in fundamental research based on high-resolution electronic states of molecules on metals, concerning, for example, chemical reactions, and catalysis mechanisms.

关键词： High-resolution scanning tunneling microscope (STM) imaging functionalized STM tip metal phthalocyanines molecular orbital density functional theory calculation

Fluorescence emission from excited molecular ions in intense femtosecond laser fields

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Frontiers of physics 2013年第1期8卷 34-38页

作者： Yun-Chen Wang Cheng-Yin Wu Yuan-Xing Liu Shao-Hua Xu Qi-Huang Gong State Key Laboratory for Mesoscopic Physics Department of Physics Peking University Beijing 100871 China

Strong fluorescence emissions were observed for nitrogen, carbon monoxide, and carbon dioxide molecules in intense femtosecond laser fields. These emissions can be assigned to the transitions of the molecular ions from the excited electronic states to the ground electronic states. The formation mechanisms were discussed and the lifetimes were measured for these excited molecular ions in intense laser fields.

关键词： tunneling ionization molecular orbital fluorescence

Understanding Bonding Nature of α-Keggin Polyoxometalates[XW_(12)O_(40)]^(n−)(X=Al,Si,P,S):A Generalized Superatomic Perspective

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Energy & Environmental Materials 2024年第6期7卷 176-183页

作者： Rui Li Yulei Shi Famin Yu Rui Wang Haitao Yan Boon K.Teo Zhigang Wang Department of Physics Capital Normal UniversityBeijing 100048China Key Laboratory of Material Simulation Methods&Software of Ministry of Education College of PhysicsJilin UniversityChangchun 130012China Institute of Atomic and molecular Physics Jilin UniversityChangchun 130012China State Key Laboratory for Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Institute of Theoretical Chemistry College of ChemistryJilin UniversityChangchun 130012China

α-Keggin polyoxometalates(POMs)[XW_(12)O_(40)]^(n−)(X=Al,Si,P,S)are widely used in batteries owing to their remarkable redox ***,the mechanism underlying the applications appears inconsistent with the widely accepted covalent bonding ***,first-principles calculations show that XW_(12)are core–shell structures composed of a shell and an XO_(4)^(n−)core,both are stabilized by covalent ***,owing to the presence of a substantial number of electrons in W_(12)O_(36)shell,the frontier molecular orbitals of XW_(12)are not only strongly delocalized but also exhibit superatomic properties with high-angular momentum electrons that do not conform to the Jellium *** analysis indicates that energetically high lying filled molecular orbitals(MOs)have reached unusually high-angular momentum characterized by quantum number K or higher,allowing for the accommodation of numerous *** attribute confers strong electron acceptor ability and redox activity to XW_(12).Moreover,electrons added to XW_(12)still occupy the K orbitals and will not cause rearrangement of the MOs,thereby maintaining the stability of these *** findings highlight the structure–activity relationship and provide a direction for tailor-made POMs with specific properties at atomic level.

关键词： first principles molecular orbital polyoxometalate redox activity superatom

Methyl orbital signatures in 2-amino-1-propanol

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Chinese Physics B 2012年第7期21卷 235-240页

作者：王克栋段坤杰刘玉芳 College of Physics and Information Engineering Henan Normal University Department of Mathematics and Physics Henan University of Urban Construction

Electron density distributions of 2-aminoethanol （2AE） and 2-amino-l-propanol （2AP） are calculated in both the coordinate and the momentum spaces using the B3LYP/TZVP method. Using the dual space analysis, molecular orbital signatures of the methyl substituent in 2AP are identified with respect to 2AE. Relaxations of the geometry and the valence orbital in 2AP are found to be due to the insertion of the methyl group. Five orbitals, not four orbitals, are identified as the methyl signatures. They are orbital 5a in the core shell, orbitals 9a and 10a in the inner valence shell, and orbitals 15a and 16a in the outer valence. In the inner valence shell, the attachment of methyl to 2AE causes a splitting of its orbital 8a into orbitals 9a and 10a of 2AP, whereas in the outer valence shell, the methyl group results in the insertion of an additional orbital pair of 15a and 16a. The frontier molecular orbitals 21a, 20a, and 19a are found to have no significant role in the methylation of 2AE.

关键词： electron density distribution orbital signature of methyl molecular orbital

Ab initio study of the transition-metal carbene cations

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Science China Chemistry 1999年第1期42卷 83-88页

作者：李吉海冯大诚冯圣玉 1. Chemical College of Shandong University 250100 Ji’nan China

The geometries and bonding characteristics of the first-row transition-metal carbene cations MCH 2 + were investigated byab initio molecular orbital theory (HF/LAYL2DZ). All of MCH 2 k are coplanar. In the closed shell structures the C hlnds to M with double bonds:while in the open shell structures the partial double bonds are formed. because one of the σ and π orbitals is singly occupied. It is mainly the π-type overlap between the 2p x orbital of C and 4p x , 3d xx orbitals of M+ that forms the π orbitals. The dissociation energies of C—M bond appear in periodic trend from Sc to Cu. Most of the calculated band dissociation energies are close to the experimental ones.

关键词： transition-metal carbene cation geometry molecular orbital bond dissociath energy ab initio calculations